After three brilliant but commercially unpalatable albums with his prog-art-funk-fusion septet, Mwandishi, Herbie Hancock needed a hit. His new band, the Headhunters, was exactly what the people wanted, apparently; two of this album’s four tracks, “Chameleon” and “Watermelon Man,” have been sampled on about 1000 hip-hop tracks each. And the lesser-known flip side, “Sly” and “Vein Melter,” is every bit as potent. Airtight funk grooves that allow Hancock and reeds master Bennie Maupin to stretch out just enough to satisfy adventurous ears.