Simplicity is the key to success. According to what is know as Ockham's razor, the simplest solution is always better, and that not only applies to science, but also to music. However, jazz players and jazz listeners sometimes forget this and tend to think that jazz music has to be complex and difficult to understand, and that the more complex a tune is, the better, or more jazzy it is.
Some of my favorite standars are those who show a great degree of simplicity from some point of view. For example, most of Coltrane's songs are complex and difficult to play, but one of his best-known ones, a must for any serious player, Mr P.C. (dedicated to his bassist Paul Chambers), is easy to play and rather simple. And it is still one of the best standards ever! And the one I enjoy the most playing!
Other songs look simple but are rather complex. "Masking" the musical complexity of a tune under a nice sound and a lovely and catchy melody is an art that very few composers get to master. Jobim is, no doubt, the king of this, with tunes such as the ever-popular "Desafinado", that sound extremely simple while having a terrific harmonic complexity.
Today I was tackling a standard that I had never played before but was among my favorites: St Thomas by Sonny Rollins. And once again I realized how simplicity equals beauty, and how great players like Rollins know how to use it. Lately, I've been going back to my roots, and I find myself constantly playing one of the simplest, yet most interesting and joyful, forms of music: the blues. As I once read, blues is like chess; you learn how to play it in one day, but it takes a whole life to master it. More or less like St Thomas. I'm sure that I will never play it like Rollins but, more important than that, I will of course never be able to create a song like this. Hats off to Mr Rollins, the saxophone collosus...
I recommend you to check Jim Hall's version of St Thomas...another great lesson on how to be simple.