Miles here recorded for several months in the studio, tape forever rolling, "jam session style." Afterwards, (since there were too many cuts to be included on an LP), they selected these 2 songs for the record. Mile's producer, Ted Marceo (who had been with him since around 1958), inserted a tape on trk 1 from a previous session containing a scary muted trumpet sound. He also toned the drums down on some parts for a "drumless" effect (which would otherwise be forever playing). Herbie Hancock wasn't scheduled to be on the session. He just walked in back from the supermarket still holding his grocery bags to drop off a copy of his latest LP (today it is a CD) for Miles. He never intended to stay. But Miles had other plans. He saw how adding keys to the session could make it better. So... he just pointed to a small Farfisa organ in the corner & said "play!" Herbie had never seen the thing before and anyways, he HAD TO GO. They argued for a while but Miles was firm. At last, Herbie went over to the thing and tried to figure out how to turn it on. After that, he played his solo, gave Miles the record and left. Enjoy this CD and let's hope after all that arguing, Herbie has some energy in his solo!