Conversation so far:
What was Stan Kenton's career like?
As a pianist, composer, arranger and band leader Stan Kenton led an innovative and influential jazz orchestra for almost four decades.
Who was Gus Arnheim?
Gus Arnheim was an American pianist, and Stan Kenton was in his band before he departed.
What did Stan Kenton do after he departed from Gus Arnheim's band?
Once Stan Kenton departed from Gus Arnheim's group, Kenton went back to study with private teachers on both the piano and in composition.

Question: Where did he study?
Self-contained rewrite: Where did Stan Kenton study?