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Wednesday, December 31, 2008

QUESTIONS? ¿PREGUNTAS?

Remember, if you have ANY questions just leave them in a comment section and I'll post the answer in the same place. Or if you prefer leave me your email and I'll answer you .

Recordad, si teneís cualquier pregunta o duda dejádmela en cualquier sección de comentarios y os responderé ahí. O si quereís me dejais vuestro email y os contesto ahí.

Pentatonic modal usage (6)



Listen to this example here in Soundcloud:
Escucha el ejemplo aquí en Soundcloud:




-->
Chord tones: 1, b3, b7
Extensions: 11, b13
Chord: minor 7th and half-diminished (m7b5)
Sound: Aeolian, Phrygian, locrian. (Since there is no 9th to determine the exact minor mode to which this scale belongs, it will fit both Aeolian and Phrygian. Since there is no 5th, it also fits the half-diminishd chord).
Eólico y frigio. (Debido a que no hay una 9ª para determinar exactamente a que modo menor pertenece esta escala, se puede usar tanto en eólico como en frigio. Lo mismo ocurre al faltar una 5ª, también se puede usar con el acorde semi-disminuido o m7b5).





-->
Chord tones: 3, 7
Extensions: b9, #11, 13
Chord: major 7
Sound: Lydian b9 (Very little use) (Muy poco uso)







-->
Chord tones: 1, 5, b7
Extensions: 9, 11
Chord: 7sus4
Sound: dominant 7 sus4







-->
Chord tones: 7
Extensions: b9, #9, #11, #5
Chord: major 7
Sound: No use. Ningún uso.


Tuesday, December 30, 2008

PARA LOS QUE ESTAIS EN ESPAÑA

Imparto un curso de Improvisación en el Conservatorio Virtual. Se dan creditos válidos para oposiciones. El curso está homologado por el Ministerio de Educación y el Gobierno de Aragón.

Pentatonic modal usage (5)



Chord tones: 1, 5

Extensions: 9, 11, 13

Chord: sus4, 7sus4

Sound: a major chord where the 3rd has been substituted for the 4th. Sus4 chords.

Un acorde mayor donde la 3ª ha sido sustituida por la 4ª.






Chord tones: b7 (Note the enharmonic spelling of the b3 as a #9, it is not treated as a chord tone)

(Fíjate en que a la b3 la llamamos una #9ª, de esta forma la consideramos como extension o alteración)

Extensions: b9, #9, #11, b13 (In this case these would be called alterations, more on this later)

Chord: Dominant 7

Sound: Altered, super locrian, diminished whole-tone. (3 names for the same scale).





Chord tones: 3, 5, 7

Extensions: 9, 13

Chord: major 7

Sound: Ionian. (Great application over a major 7th chord!)

(Muy buena aplicación de esta escala con un acorde de 7ª mayor)


Monday, December 29, 2008

Pentatonic modal usage (4)

Now that we have seen the process of super-imposing the major pentatonic scale over a static bass note and have analyzed the resulting tones and chords with which it can be used, we will continue with this procedure but in a more systematic way.

Ahora que hemos visto el proceso de combinar la escala pentatónica mayor con una nota fundamental y hemos analizado los tonos y acordes resultantes, seguiremos este proceso pero de forma más sistemática.


Chord tones: 3, 7

Extensions: 9, #11, 13

Chord: Major 7

Sound: Lydian






Chord tones: 1, b3, 5, b7

Extensions: 11

Chord: minor 7

Sound: No sound characteristic of any minor mode is produced. Therefore it can be used with ANY minor chord.

No se produce ningún sonido característico de un modo menor. Así que se puede usar con CUALQUIER acorde menor.





Chord tones: 3, (#5), 7

Extensions: b9, #11, (b13)

Chord: major 7 augmented 5

Sound: With these extensions this scale has little to no applications.

Con estas extensions, esta escala tiene poquísimas aplicaciones por no decir ninguna.

Saturday, December 27, 2008

Pentatonic modal usage (3)

Remember I said we would move up by half step the major pent. scale and the fundamental bass tone would remain the same? Let’s do that, C major pentatonic is moved up a half step to Db major pentatonic:

¿Te acuerdas que dije que la escala pentatónica se subiría medio tono y que la fundamental se mantendría? La escala de Do pentatónica mayor se sube a Reb pentatónica mayor.



Notice that the resulting tones are those of a major pentatonic scale (1, 9, 3, 5, 13), only we’ve transposed it up a half step to Db major pentatonic. Now we add the C fundamental bass note, this is static so it doesn’t change.

Fíjate en que los tonos resultantes son los de cualquier escala pentatónica mayor (1, 9, 3, 5, 13), solo que se ha trasportado de Do a Reb. Ahora se añade la fundamental Do que será la nota grave del bajo y es estática, no se mueve.



The overall RELATIONSHIP, or resulting sound of C in the bass and the Db maj. pent. scale all sounding at the same time changes drastically. We have five notes that take on a sound of their own! Now we analyze each note of Db major pentatonic and see what intervallic relationship it has with C.

La relación resultante del sonido de Do con Reb pentatónica mayor cambia drásticamente. Tenemos cinco notas que tienen un sonido nuevo, diferente y propio. Ahora analizaremos cada nota de la escala pentatónica mayor de Reb y veremos que relación tiene con Do.

Let’s find the chord tones: b3rd (or minor 3rd) and b7 (or minor 7th). The chord to use this with is clearly a minor chord (minor chord formula = 1, b3, 5, b7). In the resulting five notes we don’t have the root (the bass is playing it, it’s C), nor the 5th, but we don’t need it, the b3rd and b7th firmly create the sound of a minor 7th chord.

Primero identificaremos las notas del acorde: 3ªm y 7ªm. Claramente el acorde con el cual se debe de usar esta escala es con un acorde de 7ª menor (fórmula de acorde de 7ª menor = 1, b3, 5, b7). En los tonos resultantes la tónica no está presente. (No hace falta porque la toca el bajo que es Do), tampoco está la quinta, no hace falta porque con la 3ªm y la 7ªm presentes es suficiente para identificar el acorde como 7ª menor.

The extensions or non chord tones are: b9, perfect 11th, b13. Clearly we are talking about the Phrygian sound by playing a major pentatonic scale one half step above a root.

Las extensions o notas que no son del acorde son: 9ªm, 11ª justa y 13ªm. Estamos hablando del sonido frigio. Por lo tanto tocando una escala pentatónica mayor un semitono por encima de una tónica nos da el sonido de frigio.

In an improvisation context suppose the piano player plays Dm7 and you want to give your solo a phrygian pentatonic sound over that Dm7. You need to play Eb major pentatonic. The D root in the Dm7 is the I and the Eb from the major pentatonic is the bII, therefore bII/I will always give a pentatonic Phrygian sound. Neat huh?

En el contexto de una improvisación suponte que el pianista toca el acorde Re m7 y tu quieres darle un aire frigio a tu solo. Tendrías que tocar la escala pentatónica mayor de Mib. La tónica Re en el acorde Re m7 es el I y el Mib de la escala pentatónica mayor es el bII, así que bII/I siempre dará el sonido de frigio pentatónica.

Wednesday, December 24, 2008

Pentatonic modal usage (2)

What follows is the superimposing of a major pentatonic scale, whose root will change, over a static root. This will produce the relationship of:


Any major pentatonic scale / Static (fixed) root

A continuación analizaremos el resultado de poner una escala pentatónica mayor sobre una nota estática que hará la función de una tónica. La relación que esto produce es:

Pentatónica mayor/Tónica estática (fundamental).


Cualquier escala pentatónica mayor / Tónica estática


The major pentatonic scale will ascend by half step and we will analyze the resulting tones when played over a fundamental static bass note (root).


La escala pentatónica mayor la iremos subiendo de medio tono en medio tono mientras que la nota estática de abajo seguirá siendo la misma. Esto hará que las notas de la escala pentatónica mayor cambiarán en relación con la fundamental.


At this point I will refer to all non chord tones (2nds, 4ths and 6ths) as their compound interval equivalent (9ths, 11ths and 13ths). These are also known as the extensions of the chord or scale. So:


A partir de aquí, todas las notas que no son del acorde (2ª, 4ª y 6ª) se les llamará por su intervalo compuesto (9ª, 11ª y 13ª). A estos se les conoce también como las extensiones del acorde o la escala

2nds = 9ths

4ths = 11ths

6ths = 13ths

Let’s start with C major pentatonic (1, 9, 3, 5, 13) over a root C or mathematically I/I (Maj. Pent./Fundamental static root)


Comenzaremos con la escala de Do pentatónica mayor (1, 9, 3, 5, 13) sobre una fundamental Do, o, matemáticamente I/I, Pentatónica mayor/Tónica estática (fundamental).



Note that in the “fraction” I/I, the fact that both roman numbers are the same simply means that the roots are the same. The roman number on the left will be the major pentatonic scale and it shares the same root as the roman number on the right which is the fundamental bass note.


Fíjate que en el quebrado (fracción) I/I, el hecho de que los dos números romanos sean los mismos indica que tienen las mismas tónicas, en este caso Do. El número romano de la izquierda será la escala pentatónica mayor que comparte la misma tónica con el número romano de la derecha que es la nota fundamental.


Now, we want to analyze this relationship and see the resulting tones to determine over what chord(s) it will fit.


Queremos analizar la relación entre estos dos y ver los tonos resultantes para determinar con que acordes puede sonar bien la escala.



So, when a C note is sounding in the bass and you play a C maj. pent. scale, the resulting tones are those listed above the scale. We need to see which notes are chord tones (part of the structure of the chord), that way we’ll know what type of chord it fits. Chord tones in this case are 1 = Root; 3 = Major 3rd; 5 = Perfect 5th. A clear major triad is formed inside the structure of a (or any) major pentatonic scale. So this scale must sound good over a C major chord. The 9th and 13th are the extensions or color tones.


Por lo tanto, cuando Do es la fundamental y tocas una escala pentatónica mayor, los tonos resultantes son los que figuran encima de la escala de arriba. Tenemos que ver que notas son del acorde para saber con que acorde sonaría mejor. Notas del acorde en este caso son: 1 = tónica; 3 = 3ª mayor; 5 = 5ª justa. Una tríada mayor aparece en la estructura de esta relación, por lo tanto cuando suena el acorde de Do mayor, se puede tocar Do pentatónica mayor. La 9ª y 13ª son las extensiones o los tonos que le dan “color”.

Tuesday, December 23, 2008

Pentatonic modal usage (1)

When the word “pentatonic” is used it usually brings to mind rock or blues. The pentatonic scale has a lot of usage in the jazz idiom. Many people use the minor pentatonic scale not realizing that there is a major pentatonic scale that has multiple uses for soloing over different chords.

Let’s start from the beginning.

Where does the pentatonic scale come from? We’ll start with the C major scale for illustrative purposes keeping in mind that these examples should be transposed to all 12 keys.

Note: When you see the number of a scale degree by itself, it is understood that it is a major scale degree. In the case of minor scale degrees, I will place a small “m” before the number OR a “b” (flat, ex: b3 means minor 3rd) but that does not mean that the note is necessarily flat, it means it is lowered a half step. If the “b” (flat) is after the note, then the note is flat.

Example: In the following major scale the 3 is major so it is written just as a 3, the same with the 7th degree. However in the minor scale that is below, the 3rd scale degree is a minor 3rd so I’ll indicate it as m3 (or b3) and the 7th also as m7 (or b7). Perfect intervals will also be indicated as just the number)


A menudo la gente piensa en rock o blues al escuchar la palabra “pentatónica”. La escala pentatónica tiene muchos usos en el mundo del jazz. Muchas veces la 1ª escala pentatónica que se aprende es una menor, pero, lo que la gente no sabe es que esa misma escala es una escala pentatónica mayor con multiples usos para improvisar sobre diferentes acordes.

¿De donde procede la escala pentatónica? Empezaremos con la escala de Do mayor y la usaremos como ejemplo.

Nota: Cuando ves el número del grado de una escala por si solo, ese grado siempre se entenderá que es mayor. Por ejemplo: los grados que forman el acorde de Do mayor son 1, 3, 5,. El 3 es mayor (Recuerda que 1, 4, 5 y 8 con grados o intervalos justos y no mayores ni menores). Para indicar un grado menor pondré una “m” o “b” (bemol) delante del grado, esto significa que el grado es menor.



Any major scale has 7 notes. Pentatonics have 5 notes so we have two too many. Here’s the rule: Remove the 4th and 7th degrees from any major scale and the result is a major pentatonic scale.


Las escalas mayores tienen 7 notas, por lo tanto para construir una pentatónica nos sobran dos. La regla nos dice que para crear una escala pentatónica mayor hemos de quitar de la escala mayor el intervalo del tritono que es la 4ª aumentada. El 4º grado y el 7º grado. En este caso Fa y Si.



The 4th and 7th degrees form the tritone that is found in a major scale. A mathematical formula for this major pentatonic is: 1 2 3 5 6.


Nos quedamos con Do pentatónica mayor. Su fórmula matemática es 1, 2, 3, 5, 6. Esta es la fórmula para cualquier escala pentatónica mayor.


Friday, December 19, 2008

Smoke gets in your eyes

Here's a copy of my arrangement of the classic tune "Smoke gets in your eyes" by Jerome Kern. Farther on we'll analyze this arrangement because there's all kinds of stuff going on. In the meantime you might want to get familiar with it. The first thing I did was change the key to accomodate the arrangement so that it "sits" better on the guitar. This is a very common technique and sometimes a necesity when arranging for the guitar.

Aquí teneis una copia del arreglo mío del tema "Smoke gets in your eyes" de Jerome Kern. Más adelante analizaremos este arreglo ya que hay mucho que ver. Mientras os podeis familiarizar con él. Lo primero que hice fue cambiar el tono para que se acoplara mejor a la guitarra. Esta es una técnica común y a veces necesaria cuando se hacen arreglos en la guitarra.






Monday, December 15, 2008

¿Quereis que traduzca este blog al español?

Si quereis que traduzca este blog al español, dejadme un comentario aquí por favor. Si tengo bastantes peticiones lo haré.

Si teneis preguntas, sugerencias o dudas, dejad un comentario y si quereis que os avise si hago la traducción, dejad un email..

Un saludo a todos

Walking bass for guitar (3)

Here are some variations on what we've seen up to now. You're probably starting to see that there are many possibilities to walk from one chord to the next.

If you can get two or three "stock" walking bass lines under your fingers then you will eventually be able to comp and walk for many standards. I concectrated on learning two or three walk/comp patterns for ii-V-I's (in major and minor) and we all know how common that progression is!

By the way, we'll get to the comping part soon.

Here are the variations to help you get ideas, or use these:

Walking bass for guitar (2)

Let's try a descending walking bass line.



Notice that in both examples seen up to now, the 5th of the Dm7 chord falls on beat 3. If we had tried a scalar approach in this example we would have started on the root "D", descended to its 7th "C" and on beat three would have landed on its 6th "B". Not a good note for the 3rd beat. Bass players strive to play roots on beat 1 and 5ths on the beat 3. It defines more clearly the harmony. Again we finish with a chromatic note to lead us smoothly into the root of the new bar.

Sunday, December 14, 2008

Walking bass for guitar (1)

I'm going to take a break from the fingerstyle arrangement of "All the things you are" to talk about walking bass on the guitar. I touched on this just a bit in the arrangement and said that I'd do a lesson on it. This lesson also applies to bass players, after all it's thanks to them that we have this technique.

Voy a hacer un parentisis y hablar de como se hace una línea tipo "walking" en la guitarra. En el arreglo de "All the thing you are" vimos un poco una línea de estas pero no se habló en como se construye. Los bajistas también se beneficiarían de esta lección.

First you have to learn how to construct a walking bass line.

I don't know who started to play walking bass on the guitar but I think that Joe Pass raised it to the modern standard that it enjoys today. For guitarrists it's trickier simply because we now have to do two or three things a t once and that limits us quite alot. But that doesn't stop us. Walking is a technique that gives alot of movement to a tune.

No sé quien inventó el "walking" en la guitarra pero sé que Joe Pass lo elevó al nivel de que goza hoy en la guitarra. Para un guitarrista es más difícil por que además de la línes de "walking", tenemos que acompañar y eso nos limita. Pero si logramos superar esta dificultad añadida, el "walking" da mucho movimient a un tema.

There are many definitions for walking bass. The two recurring words in the definitions I've seen have been "chromaticism" and "swing". In other words you arrive at the next note in the bass line by a half step. OK, but I've used chromatics in my bass lines in Bossas and Bossas don't swing. I have also heard the bass line playing the notes of an arpeggio on every beat of a 4/4 or 3/4 swing tune with no chromaticisms and the tune had swing. So, where does that leave us? I've come up with my own definition that I feel satisfies the definition of what a walking bass line is:

Playing on the beat (1, 2, 3, 4 in 4/4 time), bass notes from the scale OR the arpeggio of the chord that's sounding at that moment, with a heavy usage of chromatic approach tones to connect to the next chord.

Una de las muchas definiciones para la línea se "walking" es:

Tocar en los tiempos fuertes (1, 2, 3, 4 en un tema con compás 4/4), las notas del bajo de la escala O del arpegio del acorde que está sonando en ese momento y el uso de cromatismos para conectar la línea al siguiente acorde.

There's alot in that definition but we'll take it apart slowly and you 'll understand it.

Let's start with some basic rules to follow that I have found to work over and over again taking alot of the mystery out of this technique:

Aquí hay unas reglas básicas para seguir que uso una y otra vez:

1-Beat 1 of a new chord starts with the root of the chord.
2-Beat 3 should (95% of the time) be one of these notes IN THIS ORDER: 5th, 3rd, 7th.
3-Beat 4 should be preferably a chromatic approach tone to a new chord or a note a whole tone away from the new chord. If the chord remains the same then use a note from the chord, the scale or a chromatic.
4-Beat 2 is up to you as long as it maintains the smoothness of the walking line.

1-En el 1er tiempo de un compás donde se toca un acorde nuevo ahy que empezar con la tónica del acorde.
2-El 3er tiempo (el 95% de las veces) debería de ser una de las siguientes notas en este orden de elección:5ª, 3ª, 7ª.
3-El 4º tiempo preferiblemente debería ser un cromatismo para entrar en el acorde nuevo por semitono o si no puede ser entonces por tono. Si el acorde no cambia, usa una nota del acorde, de la escala o un cromatismo.
4-El 2º tiempo depnde de ti siempre que no se pierda la uniformidad o suavidad de la línea del "walking".

Let's take a iim7-V7 (two minor 7-five dominant 7) chord progression and first see how a scalar walking bass is constructed:

Vamos a construir una línea "waling" con las notas de la escala en una progresión iim7-V7:


We immediately see that if we choose a scalar approach for this example then on beat 4 we would have to play a G which is the root of the chord in the next bar. So we would have arrived at the G7 too early. That's why we introduce a chromatic note. This concept adds a very smooth bass line moving by half step into the root of the next chord.

Enseguida vemos que si elegimos usar notas de la escala, que en el 4º tiempo tendríamos que tocar un Sol que es la tónica del siguient acorde. Por lotanto habríamos llegado demasiado pronto al acorde de Sol7. Es por eso que se introduce el cromatismo.

I will critique your work for free!

If anybody who's following this blog would like to apply the lessons we've seen up to now on "All the things you are" and attempt to do the next four bars on their own, you can send me your arrangement and I'll critique it personally and write back to you with the results! Or if you wish to do an arrangement of another tune that's fine also.

Send your arrangement to: rhrz@wanadoo.es, BUT, you MUST write a comment in this blog that you are sending me your arrangement. Tell me your name or a nick that I can identify on the email you send. If I don't get a comment on this blog from you I won't open the email and I'll erase it. You can send an mp3, tab or music notation.

Also if you'd like to see any lessons in particular posted here just suggest them to me.

Saturday, December 13, 2008

Guitar arrangements: How to do them (6)

Now that we've seen (and heard) how a walking bass line sounds with only melody and bass, the next logical step is to add some harmony.

Listen carefully to how a piano or guitar accompanies a soloist (sax, trumpet...) in medium to up tempo tunes. Most of the time the chords played are very short in duration. We call this way of accompniment or comping, "hits" or "stabs" and what's most important about this is not the harmony itself because it's so short that at times you barely perceive it, IT'S THE RHYTHM. Notice that these harmonic "hits" rarely are played on strong beats but are played on weaker upbeats. If you play to much harmony on strong beats then the tune gets sluggish like a car trying to get out of deep mud. But if upeats are the focus of where you place your chords then the tune is a Ferrari.

So with that in mind here's walking bass, harmonic "stabs" and melody. (Note: In jazz all upbeat quarter notes are always played short unless noted otherwise)



This is pretty tricky fingerwise. Practice two notes at a time and go slowly. I recommend Tuck Andress' DVD "Fingerstyle Mastery".

Thursday, December 11, 2008

Left hand finger stretching exercise

Here's a simple stretching exercise that really helped me. Remember don't push your fingers too much, just enough to feel them stretch, never to the point of pain. If you do feel pain then stop and continue the next day. Better to rest one day than to have to stop all together for several weeks because you've torn ligaments and tendons, right?

A few rules to follow with this exercise:
1) Keep your fingers on the fret board at all times. Don't "pick up and put down" any fingers.
2) Keep your fingers as close to the frets as possible. It'll be hard to do when you go to move finger 2 (middle finger) because it'll want to drag finger 3 (ring) with it.
3) This is a stretching exercise so sound is not that important. Don't get hung up on fret noise or if one string doesn't sound 100%. Get the fingers on the fretboard and just do it.
4) As the exercise progresses down the fretboard the harder it'll get because the fret spacing is wider. Hang in there.
5) Good luck!

Guitar arrangements: How to do them (5)

Let's continue with our arrangement of All the things you are. I'm going to introduce a walking bass line at this point. I was debating whether to temporarily stop the arrangement lessons of this tune and do several on guitar walking bass or continue with the arrangement and at a later date do the walking bass lessons. I've opted to continue with the arrangement for the sake of continuity. So I'm going to write out the walking bass part and explain later how to construct one and how it works.

Again there are several ways of combining the three elements (bass/harmony/melody). I'll go from simple to complex.

This first version contains just bass and melody. It lends itself to speed since at any given moment you're only playing two strings or just one if the melody is resting or has a long note value as in the first bar of this tune. It can be used as a nice interlude, solo break, intro, use your imagination.



There is no actual harmony as you can see. It is implied by the relationship between the bass and the melody. Keep the melody sounding for the duration of its notes!

Some of the fingerings are real stretchers but are doable. Don't force your fingers if they won't stretch, you can end up hurting yourself. It might take some players a little longer to achieve this. That's OK, it took me quite some time. Here's a good video on how to do this. I'll write out in a post some of the excercises I've used (see the post above this one titled "Left hand finger stretching exercise").

A word on bass lines. Bass is one of the least understood and most important instrumnets in any group. Bass lines create smoothness and a firm foundation on which everyone else in the band builds their creation. If the bass lines are not working the whole band sounds like muck. So, it is very important to keep the bass sounding for the full length of its value. Avoid short bass notes (in this style) and keep the transition from one to the next as smooth and uniform as possible.

Listen to Tuck Andress, Martin Taylor, Joe Pass, etc..... they are masters at it and it gives the music so much movement.

Guitarra Jazz Rítmica: El Arte de Acompañar.

CONOCIMIENTO TOTAL Y COMPLETO DEL MÁSTIL DE LA GUITARRA.
COMO CONSTRUIR Y USAR TODOS LOS ACORDES (Y SUS ALTERACIONES) EN LA GUITARRA.
Ya a la venta,
Guitarra Jazz Rítmica: El Arte de Acompañar. ¡EN ESPAÑOL! Este libro te convertirá en un guitarrista avanzado en cuanto a conocimientos de armonía y teoría en el mástil y te enseñará como emplear en la vida real los conceptos explicados en él. Te convertiras en un guitarrista muy solicitado. Con ejemplos prácticos en notación musical y TAB. Ver en la columna izquierda bajo "libros" para ver el índice y contenido del libro.

Este libro es una compilación de mis años de estudio tanto a nivel universitario como profesional e individual. Expongo lo que he aprendido en la práctica, por lo tanto, todo en este libro es de gran utilidad.

Si siempre tocas los mismos acordes y te falta variedad rítmica, armónica y melódica en tu forma de tocar, éste es el libro que te abrirá nuevos horizontes y ampliará enormemente tus conocimientos del mástil.

En la columna de la izquierda de este blog busca el nombre del libro (Guitarra Jazz Rítmica: El Arte de Acompañar) y pincha (clic) sobre él para ver algunos ejemplos del libro. El libro contiene 80 páginas.

Precio: 30€. Se paga por giro postal (o similar, Western Union, etc...), ingreso a cuenta bancaria (España solamente) y cuando reciba el pago recibirás por email el libro en formato PDF. Si prefieres el libro en papel y encuadernado, consulta para los gastos de envío y encuadernación.

Interesados pueden contactarme enviando un e-mail a improvrrz@gmail.com. Como referencia poned el título del libro.