Poco formed out of the break-up of Buffalo Springfield in 1968... other members formed CSN, Crosby, Stills & Nash. (Steven Stills, Jim Messina, Ritchie Furay, Dewey Martin, Jim Palmer and Neil Young were in Buffalo Springfield)
One of my favorite Poco tunes is Heart Of The Night.
A little known Buffalo Springfield favorite of mine is Nowadays Clancy Can't Even Sing, written by Neil Young and sung by Stephen Stills.
Okay, Bluebird too.