There are several versions of Acker playing "In a Persian Market", all of them worth checking out. This one (from the movie It's Trad, Dad) is among my favorites, if only because we get a closeup of Acker's technique and a chance to see the stump of a finger he managed to play with on his left hand. Other than Pete Fountain, very few Trad clarinetists have had the ability to 'lift' a band the way Acker could, with a type of soaring power. While his technique wasn't as fluid as Fountain's, he had the ability to turn even novelty tunes into uplifting achievements -- a quality all but entirely lacking in modern jazz. There's a sense of fun, humor, and joy here at an unusually high level.
[ This is not a comprehensive list, nor is it representative of the "most important" or "best." Instead, following Duke Ellington's adage that the greatest music and musicians are "beyond category", I'm starting 2020 by sharing 100 jazz tunes I feel everyone should have the chance to hear--really just tunes and performances that I love. ]