Miles Davis Unplugged at Plugged Nickel : The vaults: The first unedited compilation of the trumpeter’s live recordings in the Chicago club will be released in an 8-CD boxed set Tuesday.

It was one of those proverbially cold and wintry nights in Chicago. Three days before Christmas, the chilled city was bustling with Yuletime activities.

Chicago always has been a haven for jazz and blues, but on Dec. 22, 1965, at a small nightclub on the North Side called the Plugged Nickel, it was about to become one of the seminal focal points for post-be-bop, contemporary jazz. Miles Davis had come to town to make a live recording.

Davis had family in the Chicago area and liked to spend the holiday season in the Windy City. And the excitement surrounding the booking at the Plugged Nickel was heightened by the fact that it was to be one of his first performances in many months, after having been laid up by surgery since mid-April.

Columbia Records, concerned that Davis’ career might be adversely affected by rumors about his physical condition, decided to make a bold statement by recording the trumpeter in a “live” setting. The mobile tape equipment was rolled in and the entire performances of Dec. 22 and 23 were preserved.

Bits and pieces of the sessions have been available over the years, initially in Columbia’s “Cookin’ at the Plugged Nickel” and “Live at the Plugged Nickel,” CBS Sony’s “Miles Davis at the Plugged Nickel in Chicago, Vols. 1 and 2” and in 1992 in an allegedly complete collection from Sony Japan.

But the first truly unedited compilation--including every note from the seven sets played over those two evenings by the quintet--will be released Tuesday by Columbia on an eight-CD boxed set titled “The Complete Live at the Plugged Nickel, 1965.”

(Also in the works, scheduled for possible release this fall, is a six-CD boxed set of the complete Davis/Gil Evans recordings for Columbia, including a full CD of previously unreleased material. And, expected next spring, another boxed set of the complete recordings by Davis’ ‘60s group.)

The recordings were assembled and repackaged by producer Michael Cuscuna and creative adviser Bob Belden, a highly regarded composer, arranger, producer and authority on Davis and his music.

“One of the most important things we did,” Belden says, “was to restore about 30 minutes from the original three-track tape that had been cut from previous releases.”

Cuscuna and Belden, working with two tapes that had been made concurrently at the club, also rebalanced the sound and added less reverberation.

The result is a kind of time trip to a mid-’60s jazz club, surrounded by ambient room noises, audience rustles and musicians’ off-handed comments. Aside from the music, which--as in any continuous sampling of a live performance--has high and low spots, the general atmosphere triggered by the audio is astonishingly engrossing.

Davis’ presence is almost palpable, instantly calling up images of his carefully tailored persona of the period, strolling the stage, striking his classic pose as he pushed the Harmon-muted bell of his trumpet into the microphone. His sound is equally up front, via open and muted horn, as he probes his way (occasionally in multiple renderings) through such familiar items as “ ‘Round Midnight,” “My Funny Valentine,” “Walkin’,” “On Green Dolphin Street,” “If I Were a Bell” and no fewer than four versions (in the seven-set program) of “I Fall in Love Too Easily.”

Davis’ group of the era was one of the most influential ensembles in jazz history, an eager band of adventurous young players--pianist Herbie Hancock was 25, bassist Ron Carter was 28, tenor saxophonist Wayne Shorter was 32 and drummer Tony Williams had just turned 20--who were gathering, synthesizing and transforming the turbulent currents coursing through jazz in the ‘60s.

What makes this collection even more arresting is the manner in which Davis and his sidemen reached into such expansive improvisational areas while performing a program that, with the exception of “Agitation,” consisted of standards and material from earlier repertoire.

Curiously, Davis’ studio recordings of the period--”ESP” and “Miles Smiles”--although based on originals (including “Agitation”) and visibly moving toward the future, are far less exploratory than the Plugged Nickel date.

Over the course of his career, Davis was recorded in every imaginable environment. And, like many improvisational players, his premier efforts often took place outside the studio, kindled by a stimulating interactivity with a responsive crowd.

This two-night window on Davis, performing at the peak of his skills in partnership with one of his finest groups, provides both an invaluable historical document and a constantly mesmerizing listening experience.

* “The Complete Live at the Plugged Nickel, 1965,” Columbia/Legacy. Eight - CD Boxed Set. $129.98. Also available in a 10 LP, limited edition box from Mosaic Records, $130. Mosaic recordings are available from Mosaic Records, 35 Melrose Place, Stamford, Conn. 06902. (203) 327-7111.