[1.V] Jazz, Fake Books, and Improvisation
It is important to learn contemporary music because it is educational (music theory, freer expression of music, compositional skills), transforms you into a true performer, widens your audience, creates many performance and income opportunities, makes you a more complete musician, gives you a greater sense of empowerment, and is a lot of fun because, compared to classical music, you get quicker rewards for a given investment of time.
Although there is a general feeling that this genre is easier than classical, it still takes considerable work to master. What is the most important skill you need to learn? CHORDS! Basic chords (3-note), inversions, major/minor, dominant 7th, diminished, augmented, larger chords, and how to use them – combining hands, arpeggios, fast broken chords, rhythmic jumps, etc., and there is a different set for every note (tonic) on the piano! This is a huge number of chords; fortunately, you can start by learning just a few of them. You also need to learn all the scales, their proper fingering, and to coordinate the RH melody with the LH accompaniment (these are the reasons why learning classical gives you a big edge). You will also have to know all about the circle of 5ths and chord progressions. Therefore, you may be playing the simplest things in a matter of weeks; but it will take a year for most students to feel comfortable with this genre. For example, there is no such thing as true improvisation for at least a few years because true improvisation is just as difficult in this genre as composing is, in classical. What is generally referred to as improvisation is "practiced improvisation" in which you have practiced a set of optional changes to pick from, and these changes usually follow a set of rules.
I review some literature in the "Jazz, Fake Books, and Improvisation" book review section; these will give you a good idea of how to get started. You might begin with Blake's "How to Play from a Fake Book". Fake books are simplified sheet music in which only the RH melody and the associated chords are indicated. It is up to you to decide how to play these chords – this is why you need to learn all about chords; not only are there so many of them, but each can be played in many different ways. Therefore, learning all about chords is where you will initially spend most of your time. Fake books are the easiest to start with because you don't have to know chord progressions – they are given to you on the sheet music. See the book review in the Reference for more information on Blake's book.
The next reviewed book to use is "How to play the piano despite years of lessons" by Cannel and Marx, which is not a book about technique; instead, it teaches how to play jazz, popular songs, or from fake books. Again, we learn all about chords but, in addition, we learn about the circle of 5ths and chord progressions, so that you can "play by ear" – remembering a melody, you should be able to figure out the melody with your RH and add your own LH without a fake book. Gets you started immediately by playing simple stuff – read the review for more details. This is the only book of the 3 discussed here that treats rhythm, which is very important in jazz.
A third book you may want to read is Sabatella's "A Whole Approach to Jazz Improvisation" which is basically a detailed definition of all the chords and scales, as well as discussions of jazz history and what music you should listen to, as examples of how they are played. This book can be browsed free (see review), but there are no songs or music to play – just theory and discussions.
Perhaps the happiest finding in all this is how restrictive the chord progressions are, in terms of the circle of 5ths (see Cannel & Marx, Sabatella). This makes it easy to get started, and to advance progressively into more complex music. We must all learn the circle of 5ths because it is needed for tuning the violin, learning how to tune the piano in the temperaments, understanding those temperaments, figuring out all the scales, their chords, and the key signatures, as well as understanding music theory. But why does the human brain respond in this way to the circle of 5ths? Is it because we have become accustomed to the chromatic scale which is a direct byproduct of the circle of 5ths, or is there an underlying biological origin? As alluded to by Mathieu, there is an instinctive mental affinity to the small primes (1, 2, 3, 5, 7, etc.) in terms of harmony; the prime 1 is the unison which is just one note and does not produce much music, although Phillip Glass uses it a lot in his compositions. 2 is the octave and is used only as small parts in larger compositions (Fur Elise). 3 is the circle of 5ths and gives birth to the chromatic scale, all the music we play, and the chord progressions. There is nothing "natural" about the chromatic scale. It does not exist in nature and is a purely human construct that is useful because the notes are sufficiently closely spaced, and span a sufficiently wide frequency range, so that we can represent practically any music with it; it also approximates the principal intervals (which exist in nature) that the brain recognizes. In the absence of research results, my personal opinion is that chords and chord progressions are recognized by the brain because of the logarithmic response of the ear to frequencies. The reason for the logarithmic response is that it covers a wide range of frequencies. This response makes frequency ratios particularly easy to track in the brain because all frequencies of a ratio are equidistant from each other in logarithmic space (possibly, right in the cochlea). Chord progressions are not only ratios but any single change along the circle of 5ths leaves at least one note common to both chords, making it especially easy for the brain to calculate the frequencies of the new chord. Therefore, chords and chord progressions along the circle of 5ths represent the simplest sets of frequencies for the brain to process. Introduction of any other frequency will create horrendous problems for the brain in terms of memory and processing. Thus harmony and chord progressions have some biological basis in addition to our tendency to become "addicted" to any music scale that we hear frequently. This addiction may be related to a biological need to recognize each other; for example, how does a mother penguin recognize its chick just from its chirp among thousands of other chicks, after returning from a long feeding trip? It is a built-in biological addiction to a familiar sound. However, this biological explanation still leaves open the question of why almost every music ever composed has a tonal key, and why the music must return to this tonal key in order for it to be resolved (end satisfactorily). The brain somehow recognizes a certain key as "home" and must return to it.
In summary, the process of learning this genre consists of practicing the chords and scales sufficiently so that, given a melody, you can "feel" the right and wrong chords that go along with it. This takes a lot of playing and experimentation. Alternatively, you can learn to recognize the chord progressions, which is not easy either, and develop a sounder approach using theory. Therefore, if you take a long term approach, and start with a few simple pieces and gradually add more complexity, you should be quite successful. It is important that you perform these pieces you learn as soon as possible, and to critically assess your strong/weak points and work to improve your performances. Because this genre is still young, the instruction books are not all consistent; for example, the circle of 5ths in Sabatella goes clockwise with respect to the sharps, but goes counter clockwise in Cannel and Marx, and exactly how you should use the 7th chords depends on which book you read. It is clear that this genre is here to stay, has great educational and practical value, is relatively easy to learn, and can be a lot of fun.