Cash is the leader of the "Singin' Strays" group, and from the very beginning of the movie it seems to be that he doesn't get along with Dixie very well. They get into an argument after he fires her and it spirals to the point where he asks Copper to join into the group, causing a gap to form between Copper and Tod.
After talking with Dixie, Tod accidentally lets out a secret of Copper's that eventually leads to mass chaos during the fair, eventually leading Copper to get kicked out. Cash's band members feel sorry about it, so they end up splitting apart the band.
In the end, though, Cash's band all comes back together, and Tod and Copper make amends.
Gallery
A Singing Strays sign with Cash and his band on it
Cash singing with Copper and the Singin' Strays
Cash with Dixie
Trivia
His name also supports the fact about how he takes credit for himself.
Cash is clearly named after the legendary country singer, Johnny Cash.
He is the only animated character Patrick Swayze voiced.