Of all the great jazz LPs that got lost in the shuffle of the digital revolution, "Roger Kellaway Cello Quartet" is among the most coveted. Originally on A&M, it went out of print not long after its original release in 1970, and since then has only been available on the used-LP market for extortionate prices. Now Verve has reissued it on CD, giving a new generation of listeners the opportunity to hear this radically original album for the first time.

To Kellaway fans, that's stop-press news -- but what if you've never heard of Roger Kellaway? Welcome to the club. He's the quintessential musician's musician, passionately admired by his colleagues and unknown to the public at large. What's more, I can see why. Just as Kellaway has never fit into any known stylistic pigeonhole, so is "Roger Kellaway Cello Quartet" all but uncategorizable. To be honest, I'm not even sure it's jazz, though much of it sounds like jazz. "The idea that anything can go with anything is very appealing to me," Kellaway told me in a 1995 interview, "and classical music has taught me that the options are infinite." This album proves his point, gorgeously and gloriously.

Start with the instrumentation: Kellaway on piano, Chuck Domanico on bass, Emil Richards on marimba and percussion, and Edgar Lustgarten on . . . cello? Surely not. A charter member of Arturo Toscanini's NBC Symphony Orchestra, Lustgarten couldn't have faked "Happy Birthday" without the sheet music in front of him. But Kellaway loved the cello ("It resonates with the body to a greater degree than perhaps any other musical instrument"), so he wrote out Lustgarten's parts note for note. Oh, yes, one more thing -- no drums. "The cymbals and drums in a regular drum set fill up the air between the other instruments," Kellaway explained. "Take them away, clear the air, and you get chamber music."

That's about as close as I can come to describing the Cello Quartet: It played jazz-flavored chamber music, or maybe vice versa. "Sunrise," my favorite track, opens with an out-of-tempo duet for cello and piano that sounds as if Ravel had dropped by the studio and sat in. Then Richards strokes a bell tree and Kellaway slips stealthily into a supple, mysteriously asymmetrical riff, and as Domanico lays down an off-center bass line, you start counting on your fingers and realize that the tune you're hearing is in 15/8. That's the kind of compound time signature you'd expect to hear in a piece like "The Rite of Spring," only "Sunrise" doesn't seem the least bit "modern." All its complexities dissolve in a radiant wash of rich, outdoorsy colors, and what materializes in their place is an impressionist soundscape of the utmost elegance and serenity.

Needless to say, Kellaway's airy, sparkling piano playing is everywhere evident, but the star of this CD is the group itself. Never in the history of jazz has there been a band remotely like the Cello Quartet. Listen to its debut album and you'll wonder how "Roger Kellaway Cello Quartet" could possibly have remained out of print for 34 years. It's a lost masterpiece whose time has come.