Charlie "Yardbird" Parker, the greatest improviser jazz has ever known, was a driven genius who never played anything the same way twice and whose rhythmic, harmonic and melodic sensibilities signaled the advent of modern jazz. When the wizard of be-bop died in 1955, only a few of his records were in print, though they now number in the hundreds.

Still, something has been missing, something long rumored in jazz circles, much desired by jazz fans and perpetually elusive to jazz completists -- a huge cache of private nightclub recordings made by one Dean Benedetti in the late '40s, when Parker was in his prime. In 1980, a phone call began a chain of events culminating in the appearance this week of an astounding 10-record, seven-CD box set from Mosaic titled "The Complete Dean Benedetti Recordings of Charlie Parker."

It contains almost nine hours of pure Bird, the whole Bird and nothing but the Bird. Benedetti, a Los Angeles musician who was also one of the earliest "ornithologists" (Parker devotees), recorded Parker, and Parker only, using a cheap, portable disc cutter from Sears, Roebuck (later switching to a primitive reel-to-reel tape deck). The instant Parker began an alto sax solo, the machines began to record; the instant Parker stopped, the machines were cut off. The result is 461 fragments, some as brief as 20 seconds, captured over 18 nights in Los Angeles and New York nightclubs in 1947 and 1948, and painstakingly restored four decades later by audio engineer and Parker authority Phil Schaap.

Charlie Lourie of Mosaic, which purchased the recordings from Benedetti's brother three years ago for $15,000, says the set is really "two stories. One is the unheard Charlie Parker, which is essential, and the other is Dean Benedetti."

It's merely incredible.

The journey from 1947 to 1990 involves grand mystery, family pride, buried treasure and the rewriting of history, as well as an incredible sonic restoration. It's a journey that fueled and fed off one of the great legends in jazz history.

The recordings -- 53 78-rpm acetate discs and 14 reels of paper-based tape -- have been variously compared by jazz scholars to the Dead Sea Scrolls, the Holy Grail, an undiscovered Shakespeare epic. For jazz aficionados and Parker fanatics, they are a revelation, though the average listener will be challenged not only by Parker's often incendiary playing, but by the collection's fragmentary nature and less-than-ideal sound. After Dean Benedetti's death in 1957, the recordings sat for 30 years in a chest in brother Rick Benedetti's bedroom closet.

After Benedetti's death, his legacy was hinted at, but negatively, in the writings of Parker biographer Ross Russell. In his 1961 novel, "The Sound," Russell thinly disguised Benedetti as Royo, a failed musician who throws his instrument away after hearing Bird play and thereafter spends years tracking and taping his idol (on a captured Nazi wire recorder), all the while providing Parker with heroin and booze; when Royo dies, the recordings disappear. In 1973 Russell rewrote much of his fiction as biography in "Bird Lives!," recycling fiction as fact. In fact, Benedetti was no pusher. He was a small-time drug user, like many musicians of the day.

"Russell did a lot of damage to Dean Benedetti's reputation," Lourie says. "In the first chapter of 'Bird Lives!,' he's a reprobate junkie and jazz leech surreptitiously setting up in a bathroom stall and secreting a microphone behind the stand. Russell represented him as being the drug dealer to the jazz community and Bird's source, which bordered on libel. One of the commitments I made to Rick Benedetti when he sold me the recordings was that we would set the record straight."

Though Russell portrayed Benedetti as a failed musician, he had actually put together the first be-bop band on the West Coast, which included trombonist Jimmy Knepper, who was often with Benedetti on his recording adventures. There was nothing underhanded about what Benedetti did; he made his recordings with Parker's approval.

Benedetti became a Parker acolyte the first time he heard Bird in 1945. Living in Los Angeles, he began to study Parker's commercial 78s, transcribing his improvisations and gradually incorporating Parker's groundbreaking harmonic, rhythmic and melodic ideas into his own playing.

When Parker came to play in California in 1946, Benedetti caught him often, and soon after Parker's six-month internment at Camarillo State Hospital (the result of heroin and alcohol abuse) Benedetti recorded him at the Hi-de-Ho Club. Four hours of low-fidelity Parker solos recorded between March 1 and March 13, 1946, appear in the Mosaic box, "recordings done in primitive form, with lesser equipment, by an amateur," Schaap concedes, adding that there's also "40 years of damage and the time line of Benedetti's own recording gear {and engineering skills}. Where he's at his worst, his equipment is newer, and where he's at his best, his equipment is diminished."

The following year Benedetti went to New York, recording Parker one March night at the Three Deuces and over the course of a week in July at the Onyx. By then Benedetti was already exhibiting signs of myasthenia gravis, a rare, degenerative muscle disease, and eventually he moved back West. In 1953 Benedetti returned with his parents to their native Italy where he died four years later at the age of 34 -- the same age at which his idol Parker had died two years earlier.

When he went to Italy, Benedetti left his recordings with an uncle in California; in 1955, he wrote to the uncle, asking him to "make sure they stay in my trunk -- locked up so the kids and the mice can't get to them... . They were recordings I made of the famous saxophonist Charlie Parker -- he just died and one record company has already offered me $10,000 for them."

Nothing ever came of that, and when the uncle died in 1959, the trunk was retrieved by Rick Benedetti, who packed it away in his closet. Over the years, even as the Russell books fueled dozens of rumors, no one contacted the family, and, Lourie says, "even when some folks corresponded with Rick, he never told them he had the material."

This was for two reasons, Lourie believes. "It was painful for Rick to even contemplate going near {the trunk} because of his great love for his brother. The loss was apparently quite painful. I think another part of him felt it was an annuity and later on in his life he wanted to do something for his son and he felt this was his legacy as far as financial security was concerned."

Rick Benedetti died in August, as the Mosaic box was nearing completion. His son Dean, a pro tennis player and teacher in California, said last week that "the music is very valuable and beautiful but it was more the emotional relationship and the memory of his brother that my father was concerned with."

Capturing the Moment In its mail-order brochure, Mosaic describes the sound quality of the Benedetti recordings as varying from "quite poor to fairly good," but Parker's brilliant musical ideas, and the emotion behind his playing, come through loud and clear. So does Benedetti's passion.

"Benedetti didn't record this stuff for posterity," says Mosaic's Lourie. "He was just absolutely obsessed. He wanted the key to study Charlie Parker's music and learn to play that way. He was a very serious jazz musician who recognized very early Charlie Parker's genius. Not too many people recognize genius as it's happening -- they need the benefit of time perspective -- but Benedetti realized Parker's extraordinary gift at the moment."

"It's like getting the notebooks of the ultimate influence in modern jazz," says Schaap, who has spent the last two years identifying and cleaning up the recordings. "It's like Leonardo da Vinci's notebooks, except they're actual working models.

"Louis Armstrong is the only person in jazz who's had the impact of Charlie Parker," Schaap says. "By that I mean he affected music that wasn't jazz, he affected instrumentalists off his instrument, and he changed jazz music itself. And Parker did this through improvisations on alto saxophone."

The Mosaic set, Schaap says, is "mind-boggling. It adds 10 to 12 percent to Parker's total discography, but in terms of improvisations, it's closer to a 30 percent increase."

In the last decade, Charlie Parker recordings have been in a boom cycle (a relative term in jazz, of course) and in February 1980 jazz scholar Bob Porter had just won a Grammy for his production and liner notes on a reissue of Parker's complete Savoy recordings. That apparently caught Rick Benedetti's attention. In March, he made a phone call.

When Porter answered, an Italian-accented voice asked, "Does the name Dean Benedetti mean anything to you?"

"My initial reaction was skepticism because of the rumors that had existed for so many years," Porter admits. In fact, he made an appointment to meet with Benedetti during a West Coast trip around Halloween of 1980, then failed to keep it, perhaps subconsciously fearing a trick rather than a treat. "I completely forgot about the conversation," admits Porter, who did connect with Benedetti the following fall.

Like many Parker fanatics, Porter had disbelieved the Benedetti legend, which, he points out, "doesn't start to get interesting until Bird's death. Up to that point, people are taping Bird all over the place. Not every night, but every gig he recorded after the advent of the tape recorder and its common usage probably was taped by somebody someplace, off the radio or live, and there's an enormous corpus of Charlie Parker taken from private recordings and radio broadcasts. What made this interesting was that Benedetti was the first to do it on any grand scale."

After looking at the trunk, but without playing any of its contents, Porter contacted Mosaic, a small mail-order company begun in 1982 by Lourie and producer Michael Cuscuna. Mosaic ventured where most labels didn't dare, releasing boxed sets of complete recordings various artists made for small labels such as Blue Note, Pacific Jazz and Roulette. For the Parker recordings, Mosaic called in Phil Schaap, a 37-year-old audio engineer who has for many years had a daily 70-minute program devoted to Parker on Columbia University's radio station. Although the cache was discovered in 1980, it wasn't until 1987, almost four decades after it had been recorded, that any of it was actually played, and that was when Clint Eastwood was looking for unreleased Parker recordings for his "Bird" film. The Benedetti material proved to be technically unsuitable for the film, says Schaap, "but at last I knew what I was dealing with."

When Schaap began to work on the Benedetti collection in August 1988, all of it was in some state of disrepair, from the fragile paper-based tape reels with peeling oxide to the less fragile but shredding acetates. "I thought it might be a couple of weeks' work," Schaap recalls. "I put it to bed in early August {1990} and there wasn't a day that it didn't torture me somewhere along the line. It took me 300 working days to get it right for nine hours!" Washington sound specialist Jack Towers helped Schaap restore the discs, removing such sonic debris as pops and clicks.

Still, there were problems galore, some created by Benedetti's well-intentioned but amateurish recording technique, particularly at the Hi-de-Ho where he set up his portable disc cutter in a booth right next to the bandstand. Benedetti would drop the cutting head on the acetate disc when Parker soloed, yank it up when he stopped, then drop it again when he began another solo, all the while eyeballing the grooves and trying to maximize precious disc space.

At the Onyx, Benedetti made his recordings from a storage room under the bandstand, with the microphone wire snaking up through a hole in the floor.

Bob Porter points out that the Hi-de-Ho recordings are particularly significant because they catch Parker at a crossroads: He was working for the last time as a sideman (in trumpeter Howard McGhee's band) and, having recently been released from Camarillo, he was drug-free. "These are two things Charlie Parker was probably never again at the same time in the rest of his life, so it's the circumstances that make it a fascinating event.

"All the systems are in gear and he's healthy, yet Parker's at his musical leisure at a pinnacle moment of creativity," says Porter. Also, the repertoire is McGhee's, which provides a lot of tunes Parker never recorded elsewhere.

Since these were fragmented improvisations -- Benedetti seldom recorded opening or closing themes, or others' solos -- Schaap had to identify them either through occasional titles (often misleading ones), through their harmony and chord patterns or by the few notes of melody that might exist as the beginning or end of a fragment.

"It's the hardest thing I ever did in my life," Schaap says. From Schaap's restorations, Porter fashioned 64 sets approximating the sequence of the performances, programming them for pacing, sound quality and length.

Certainly it's hard to imagine anyone else doing what Mosaic has done, or doing it as well. Although there are some impressive items in the Mosaic catalogue -- including two volumes of 23 records each (with a third coming) of "The Complete Commodore Jazz Recordings" -- there is simply no precedent for this collection of genius solos.

"People chuckle and shrug their shoulders when they see these kamikaze flights that we take, yet we land on our feet," Lourie admits. "In fact, Michael and I are amazed when we come out with a Tina Brooks or an Ike Quebec or Herbie Nichols project and we actually go in the black. It's not supposed to happen that way. The record companies would look at you like you're nuts if you suggested they put out something like that."

And though Mosaic could easily cut its risks -- the Benedetti would easily fetch up to $1,000 per disc just as artifacts -- they have donated the collection to the Institute for Jazz Studies at Rutgers.

"Dean Benedetti did a great thing and the document survived," says Lourie. "We're just facilitators. Those two guys -- Parker and Benedetti -- get top billing, second billing and that's the end of the billing."

"The Complete Dean Benedetti Recordings of Charlie Parker" is available from Mosaic Records, 35 Melrose Place, Stamford, Conn. 06902-7533; the CD version is $105, the vinyl version $75, including mailing costs. Or you can request a brochure.