The Al Biles Virtual Quintet

GenJam

In the late 1970's I led something of a double life -- computer science gradual student by day, would-be jazz musician by night. I combined these lives in my thesis, which centered on software that identified the players of transcribed jazz solos a la Leonard Feather's blindfold tests. I made a tentative stab at designing a program that generated improvisations, but I bounced off the cumbersome music technology of that day and put the idea of a software sideman on the shelf as I began my career teaching computer science and information technology at the Rochester Institute of Technology.

In 1993 I took a long-overdue sabbatical leave from RIT and devoted a year to getting back into computer music. The major result was GenJam, my sideman on this CD. GenJam is a genetic algorithm that learns to improvise jazz solos under the guidance of a human mentor (myself for this CD). GenJam breeds generations of melodic ideas, which it uses to construct improvisations. It gets to look at the chord progression for the tune it is playing, and it knows what the tempo and rhythmic style will be. It also follows an arrangement for the tune, which tells it when to solo, rest for my solo, or trade fours or eights with me. As GenJam improvises to the accompaniment of a synthesized rhythm section, the mentor listens to its solo and signals good, bad, or indifferent, whenever so moved. This real-time feedback becomes the fitness for the individual melodic ideas. Periodically GenJam breeds some new ideas, using the better ideas in the current generation as parents and replacing the worse ideas with the resulting children. After a dozen or so of these generations, GenJam starts to sound reasonable, and it's time to leave the woodshed and play a gig!

The tunes and arrangements for this CD reflect my own evolution toward an eclectic and hopefully accessible sound. I am, at heart, a straight ahead jazz musician who loves to improvise. I've played in at least 500 jam sessions over the last 20 years, almost all as a member of the house band. Jam sessions are clearly the best venue in which to develop one's skills as an improviser, and the on-the-fly arrangement of tunes promotes quick thinking, careful listening, and clear communication, at least among the musicians. On the other hand, these spur-of-the-moment arrangements can be limiting, and the over-reliance on standard rhythmic styles and forms can get old.

My approach with GenJam has been to create a virtual quintet that leaves plenty of room for improvisation, both by me and by GenJam, but in a stylistic context that is more varied and eclectic than that of the standard jazz quintet. The forms I use tend to be jazz standards with a head-solos-head structure, but the rhythmic styles stray to funk, latin and (gulp) new age. I like to take a jazz tune that I enjoy and put it in a stylistic setting that differs from the original. For example, George Duke's Yana Amina has received something of a (forgive me) new age setting. Now don't gag before you hear it; I thought it would be cheesy too, but it's become one of my favorites!

There is one classic straight ahead tune on this CD, Lady Bird, and two straight ahead jazz waltzes, Up Jumped Spring, and Barbara. Lady Bird and Up Jumped Spring use a standard quintet: trumpet or flugelhorn with tenor sax on the front line; acoustic piano, bass and drums in the rhythm section. The other tunes use a variety of sounds - vibes and marimba (on Yes and No), French horn derivatives (frequently), vocal-synth backgrounds (on Song for my Lady, among others), even some classic analog synth sounds on Analog Blues.

Most of the tunes feature some trading of fours or eights between me and GenJam, which I have come to enjoy a great deal. It can be a bit unnerving, playing with GenJam, in that its technique and sense of time are impeccable, and it never plays a theoretically wrong note. I, on the other hand, flub notes now and then, but I develop my ideas better. When trading fours with GenJam, I try to play off of what it has just played or to anticipate what it might play. This often works out well, and my favorite moments on this CD are some of the resulting interactions.

For any tech weenies out there, GenJam is a C program built on top of Roger Dannenberg's CMU MIDI Toolkit. I trained five different soloists for this CD, each with a somewhat different personality. I used off-the-shelf software tools (mainly PG Music's excellent Band in a Box) to generate MIDI tracks for the rhythm section, and I programmed the harmony parts on the heads using Adagio, which comes with the CMU MIDI Toolkit. This CD was recorded using my standard setup - a Macintosh Powerbook 160 and a Yamaha MU80 tone generator (I like to travel light). The synthesized material was recorded in stereo directly from the MU80 with no added processing. The trumpet/flugelhorn track was then recorded and added to the mix with a little reverb. GenJam, as expected, needed no second takes. I, on the other hand...

Let me know what you think.

Al Biles

jab@it.rit.edu

http://www.it.rit.edu/~jab/