Bebop was not so much a break with the past as it was a logical evolution from it. Parker continued to use chord-based changes of popular standards as the basis for improvisation. But equipped as he was with surpluses of conceptual and instrumental virtuosity, the challenges posed by traditional swing no longer absorbed his full capacities. So he went looking for fresh problems to solve within the same musical material by incorporating subtle and more extended harmonic content into his improvisations and adding to that faster, more complex rhythmic zigs and zags.

As improvisation became more challenging to the best young musicians, it also became more bewildering to audiences raised on big band jazz. The intricacies of Parker's music also had the effect of making jazz more of a closed musical culture as the large general audiences backed away from the new jazz to more simple forms. The cult of hipness became something of an article of faith among Parker's followers. But as the pressures of the popular market were lifted from jazz, the music thrived playing to smaller but far more permissive audiences who appreciated the new freedom as much as the players.

Parker was born Aug. 20, 1920, in Kansas City, Mo., and came to music while in junior high school. In the late '30s he jobbed around the city, honing his technique and tone. He first recorded with the Jay McShann orchestra in between 1940 and 1942. The early 1940 radio transcriptions and the later commercial sessions for Decca show Parker pushing at the edges of the swing parameters with an explosive gift for unexpected phrasing and twists.

His progress over the next two years was striking but largely undocumented, due a recording ban imposed by the musicians union. By the time he resumed recording in 1944-'45, his dazzling improvisations at breakneck tempos ("Ko Ko," "Donna Lee," "Shaw Nuff") astonished young jazz players as profoundly as they threatened veteran ones, thus setting the new against the old and triggering the first major internecine musical controversy in jazz history.

But the battle deepened into a cultural as well as a musical war as Parker's penchant for hard drugs and hard living further defined bebop as an outlaw music with an implied lifestyle that many chose to follow.

The definitive recordings of Parker's career were made for Savoy between 1945 and '48 ("Now's the Time," "Thriving Of A Riff," "Billie's Bounce"), and for Dial from 1946-'47 ("Ornithology," "A Night In Tunsia," "Lover Man," "Scrapple From The Apple"). They sold poorly but were as profoundly influential to young post war players as Armstrong's Hot Sevens and early big band sides had been to musicians of the '30s. Even during his most innovating period Parker remained something of a mystery figure to the general public. His picture never even appeared on Down Beats' cover during his lifetime.

The third major chapter of Parker's work began in 1948, when Norman Granz began recording him in different contexts with a view toward taking his music to a wider audience. By now his major innovations were over and his repertoire had narrowed to small number of staples. But an album with string accompaniment produced a motherload of brilliant new Parker solos that would be his last major work. He died in 1955 at the age of 35 of a combination of drug related medical problems.

In 1955, Parker was elected by the Readers to the Down Beat Hall of Fame, just following his death.