@layman,
As I remember, Woody wrote that for his brother Jack, who was a movie cowboy. Jack wrote to Woody, he should come to Hollywood and work in the movies himself, big money. So Woody went west. Every year there was a big parae, maybe the Rose Bowl, I dont' remember, where all the potential western actors would ride and show off their moves in front of the bigwig stand where all the movie execs sat holding informal auditions. Woody fell off his horse. So he became a folksinger instead.