Fusion and electric avant-garde jazz are two different things. Fusion--as envisioned by Miles Davis, John McLaughlin, Chick Corea, and others back in the '70s -- combined jazz with rock and funk in a way that didn't emphasize outside playing, whereas electric avant-garde jazz (as in Ornette Coleman's Prime Time, Jamaaladeen Tacuma, Ronald Shannon Jackson, and James Blood Ulmer) savors the dissonant pleasures of the outside. But there are times when the two merge, and that is what happens on guitarist Trey Gunn and drummer Marco Minnemann's Modulator. Actually, this instrumental CD is more than a combination of fusion and electric avant-garde jazz; it is a combination of fusion, electric avant-garde jazz, and progressive rock. And Gunn and Minnemann end up sounding like a freewheeling yet coherent "duo," which is interesting in light of how Modulator was put together. Gunn and Minnemann didn't enter the studio at the same time and record as a traditional duo. Instead, an unaccompanied Minnemann recorded a 50-minute drum solo by himself in 2006, gave the recording to Gunn and asked him to compose music for his drumming. Gunn was reluctant at first, but after agreeing to take on the difficult project, he composed some music -- and from 2008-2010, he played various instruments (including guitar, bass, and keyboards) and combined them with Minnemann's drums. Of course, there are those who will argue that recording an album that way has no place in jazz -- that jazz is about real musicians playing together in real time, not musicians playing separately and later mixing it all together. But then, Modulator never pretends to be straight-ahead jazz; this is a hybrid mixture of fusion, electric avant-garde jazz, and prog rock. And as abstract and eccentric as Modulator is at times, the music is also logical; it's clear that Gunn put a lot of thought into what he added to Minnemann's drums. Music this challenging isn't for everyone, but Modulator is well worth exploring if one is the type of broad-minded, eclectic listener who appreciates electric Miles Davis and Coleman's Prime Time as much as he/she appreciates King Crimson.