NEW YORK (AP) — The chemistry felt special right from the start of the January 1983 recording session when pianist Keith Jarrett, bassist Gary Peacock and drummer Jack DeJohnette began playing "The Masquerade Is Over," a standard covered by singers from Billie Holiday to Stevie Wonder.

They had gone into a Manhattan studio without rehearsing or any arrangements, but in an outburst of creativity they needed just 1 ½ days to record enough material — mostly from the Great American Songbook, highlighted by a 15-minute gospel-flavoured, hard-grooving exploration of "God Bless the Child" — to fill three albums instead of one as planned.

At the time, the three musicians hadn't the slightest inkling that this would be the start of a musical partnership that has lasted 25 years and counting. "If somebody had told me that, I'd say you're nuts," laughed Peacock. "We just talked about we'll do this until we don't feel like doing this anymore and 25 years later we still feel like doing it," said DeJohnette, in a telephone interview from his upstate New York home.

"I think partly the reason for that is we don't play together all the time ... so we have a breath, step away from it and then come back fresh," added the drummer, who first began playing with Jarrett in the mid-'60s in saxophonist Charles Lloyd's quartet and later with Miles Davis.

This month, their label ECM marked the trio's 25th anniversary by releasing a three-CD box set, "Setting Standards — New York Sessions" that reissues their recordings from that 1983 session — the "Standards" albums, volumes I and II, and "Changes" with freer-form original improvisations.

Jarrett's trust in his partners is reflected in the fact that in the past 25 years he has not worked with any other jazz musicians, except on one 1992 recording when Paul Motian filled in for DeJohnette. Jarrett says the trio members are flexible enough to play any jazz style and hate to stay predictable.

"If you meet the perfect other two people for your needs in a musical jazz situation, why would you force yourself to go around the corner and find other people to play with?" asked the 62-year-old pianist.

Today, after 18 ECM releases that encompass 28 CDs, the three have set a new standard for jazz piano trios. While there have been other exceptional trios — including those led by Oscar Peterson, Ahmad Jamal and Bill Evans — none match the Jarrett trio when it comes to their almost telepathic interplay, stylistic range and the depths to which they plumb the standards.

Those qualities are evident on the two-CD "My Foolish Heart," a live recording from the 2001 Montreux Jazz Festival, that Jarrett released late last year.

It celebrates a broad swath of jazz history from ragtime to free, including buoyantly swinging interpretations of classic jazz tunes by Miles Davis ("Four"), Sonny Rollins ("Oleo") and Gerry Mulligan ("Five Brothers.").

"It fits with the trio's original principles because we're not playing originals of our own," said Jarrett. "However, there are tunes on it that defy what we've previously done."

Back in 1983, it was a radical notion for a contemporary jazz musician to play standards because the emphasis was on original compositions.

Jarrett had become renowned for his spontaneously improvised solo piano performances such as the 1975 "The Koln Concert," one of the best-selling jazz albums of all time.

Jarrett himself felt restricted as a composer because he had to tailor the music to the preferences of the musicians in his '70s quartets.

When ECM chief Manfred Eicher suggested a trio album, Jarrett decided to record standards which he hadn't played much since the early '60s.

"This material was so damn good, and why was everyone ignoring it and playing clever stuff that sounds all the same?" Jarrett said in a telephone interview from his rural western New Jersey home. "We know how musical these songs are. ... Jazz musicians don't have to always break down doors, there's music inside the rooms too."

The trio had previously played together on Peacock's 1977 album, "Tales of Another," which featured the bassist's own compositions.

Peacock was initially sceptical about a standards album until Jarrett told him they would have the freedom to take the music anywhere they wanted.

"The minute we started to play, it was like whew, there's something really special here," said the 72-year-old Peacock, speaking by phone from his home in New York's Catskill Mountains.

Since then the trio has kept playing except for a nearly three-year hiatus in the late '90s while Jarrett recovered from Chronic Fatigue Syndrome.

But they came back strong with the 1999 concert recording "Whisper Not" on which the pianist displayed a lighter touch as he rediscovered bebop tunes from his youth like Dizzy Gillespie's "Groovin' High".

Today, the trio still doesn't use arrangements or even a list of tunes to play each set, instead letting each concert take shape based on the hall's acoustics, their instruments' sound and the audience response.

Peacock says the trio's evolution is best expressed by the depth they've developed in interpreting standards.

"However many times we play 'All the Things You Are', we never approach it like we're going to play it again," he said. "The musical sense is this is the first time and the last time ... and that brings an urgency to it and heightened awareness."

Jarrett says that to maintain that level the trio limits itself to only about ten to 16 concerts a year in Europe, Japan and the US. But the musicians are aware that their next concert might be their last given their various physical ailments.

Peacock, who was back performing with the trio just months after major surgery in 2002, says the music itself has a healing effect.

And the 65-year-old DeJohnette added: "We have this desire to try to play the best music we can as long as we are physically able to. We're senior citizens now, but we still have a youthful spirit about us."

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