But I went over a Parker discography, and found two more unlikely names.
A surprise, but not really unlikely -- Annie Ross. The Charlie Parker Quartet With Gil Evans Orchestra - 1953 - featured the Dave Lambert singers, including Annie.
And really unlikely -- a session recorded in Montreal in either 1949 or 1953, Paul Bley on piano. It's been released as Charlie Parker -- Montreal 1953, and you can listen to it at Rolling Stone's website, although I may be the first to have actually done so. At any rate, if you see "Average User Rating -- 4 Stars," the average user is me. I was the first one to rate it. He's on three tracks -- "Cool Blues," "Don't Blame Me," and "Wahoo." Does a very nice solo on "Cool Blues."
Curiously, these three tracks are also listed in Bird's discograpjy as appearing on the Jazz Showcase album Bird on the Road, which came out in 1949 -- four years before the actual recording date? That's listed on the discography as CBC-TV Studios, Montreal, Quebec, Canada, February 5, 1953
Seems unlikely. I followed the scent to Paul Bley's website, and found this:
Bley gave violin recitals at age five. By age seven he was studying piano. He went through numerous classical teachers - including one Frenchman that had him play, balancing filled water glasses on the tops of his hands. At age 11 he graduated from the McGill Conservatory - having taken on their musical curriculum in addition to his public school education. Bley, who was known as "Buzzy" in his early adolescence, formed a band and played clubs and summer hotel jobs in the Laurentian Mountains at age 13. Four years later he replaced Oscar Peterson at the Alberta Lounge. Bley founded the Montreal Jazz Workshop and brought Charlie Parker, Sonny Rollins, Brew Moore and Alan Eager to Montreal inorder to perform with them.
And by 1950, Bley had left Montreal. So it seems likely the session was in fact 1949, when Bley was 17. But then again, there's the discography page of Bley's website. It doesn't actually include a discography -- that's a 204-page book, which you have to order -- but the site says it "includes more than 120 recording sessions from 1952 to 1994," which would put us back to 1953, and Bley back to 21.