In 1973, Herbie Hancock recorded his legendary Head Hunters album. The record was one of the first electronic jazz-fusion experiments, an amalgamation of his classic acoustic piano playing, popular funk influences such as
Sly Stone, and Han-
cock's mastery of the constantly developing synthesizer technologies of the time.

Perhaps due to the groundbreaking nature of this new sound but in spite of its giant leaps away from Hancock's traditional styles, the album was a huge mainstream success. Rock and jazz fans
alike embraced the straightforward, memorable funk of tracks such as "Chameleon;" the disc would go on to become the one of the best-selling jazz albums of all time.

But one year later, Herbie did the unthinkable. He topped Head Hunters -- with 1974's Thrust.

Like its predecessor, Thrust consists of three upbeat, solid funk grooves and one slower tune. The two albums even feature the same musicians, with the exception of intricacy master Mike Clark, who replaced Harvey Mason on the drums.

But while Head Hunters can be looked at as a pretty accessible and steady album, Thrust is an accessible but more intricate showcase of some of funk's most brilliant performers. The songs are more complicated, but the group never hits a wrong note.

All it takes is Clark's creatively catchy intro to "Palm Grease," the disc's first track, to prove that Thrust isn't just the album's title but also its intention. With the help of some interesting Latin percussion and several key changes, the song continuously stacks new levels on top of Clark's simple intro, quite powerfully thrusting this abundance of musical talent into our ears.

But Clark's influence on the album extends beyond his drum kit, for his presence is apparently enough to free up bassist Paul Jackson's mind. The man literally tears up his four strings on every track, aggressively busting away from his repetitive and controlled playing on Head Hunters. His newfound ability to totally freak the funk meshes almost telepathically with Clark's unorthodox drum domination, creating unexpected and somehow synchronized improvisation in every measure of the disc.

Take, for example, the mind-blowing concentration of musical energy in "Actual Proof." The song's strange chord progression and syncopated, illogical rhythms defy almost all musical common sense.

And even though Hancock's electric piano is sweeping and all over the place, it is hard to not focus on the rhythmic stew that Jackson and Clark cook up in the background.

Just when we think they've lost the form and everything has fallen apart, the groove comes back in and grips the listener tighter than the fashion that was popular at the time of the album's release.

Like Head Hunters' closing track "Vein Melter," Thrust's "Butterfly" is a delicate, slower song that ranks among Hancock's most beautiful compositions.

But while the former finishes out its album with a sense of mystery and a bit of a lack of closure, "Butterfly" escalates to a double-timed, soulful climax -- and is then followed by the appropriately upbeat album-closer, "Spank-A-Lee."

More sonically impressive, rhythmically complex and compositionally gripping than Head Hunters, Thrust takes the formula for fusion's greatest album and adds talent and fearless interaction and experimentation.

It may not be remembered in jazz history as being as influential as its predecessor, but the album certainly offers much more for the musical explorer to uncover.