Robert Altman wanted all the actors (the ones portraying singers) to write their own songs in ‘Nashville’. Carradine and Ronee Blakley did the best job IMO, although Blakley really was a singer already. Fine film from the greatest decade for films.
I think Barbara Harris was the best singer of the bunch. Not my favorite performer in the film, but the best voice.
“Nashville” was mocking country music. So simple, even non-musicians can write hit songs.