Conversation so far:
Did Jascha attend college?
CANNOTANSWER.
Did he make any professional musical releases during his career?
Heifetz made his first recordings in Russia during 1910-11.
What was Heifetz's most famous work?
He recorded the Beethoven Violin Concerto in 1940 with the NBC Symphony Orchestra conducted by Arturo Toscanini.
Did Heifetz play any other instruments?
of Heifetz playing the Mendelssohn Violin Concerto.

Question: Did he work with other musicians?
Self-contained rewrite: Did Jascha Heifetz work with any musicians other than Arturo Toscanini?