September 12, 1991, first day of high school. . .three hard-rocking adolescents convene in Jazz Band 101 and attempt the Miles Davis composition So What, insisting, much to Mr. Sanborn's dismay, that it be played with a driving backbeat, distorted guitar, and John Bonham drum fills. Things haven't changed all that much. The members of The Slip, brothers Brad and Andrew Barr and Marc Friedman, have been playfully altering song forms and establishing a shared vocabulary ever since.