Conversation so far:
what is Buffalo Springfield?
Stills, Furay, and Young reunited in Los Angeles and formed the core of Buffalo Springfield.
was it an album?
The band would release three albums: Buffalo Springfield, Buffalo Springfield Again, and Last Time Around.
were the albums hits?
and enjoy only one hit single.
what did he do with Crosby?
Stills played on the Super Session album with Al Kooper and joined up with David Crosby.
did they release other albums together?
Renditions of the latter's "You Don't Have to Cry," led to the formation of Crosby, Stills & Nash.
was crosby playing for anybody else before he joined stills?
David Crosby, who had recently been ejected from the Byrds.
did Stills know Nash before he worked with him?
CANNOTANSWER.
Did they go on tour?
Wanting to be able to tour and needing additional musicians, the band invited Neil Young to join them for their subsequent tour.
Which tour was this?
CANNOTANSWER.

Question: did he sing with anybody else?
Self-contained rewrite: did Stills sing with anybody else besides Nash?