Did Tom Petty ever sing Lullaby originally by Shawn Mullins, it has the lyrics: Everythings gonna be alright rock-a-bye. I'm not asking for myself but my mother would stake the family estate on the fact that he did, and she is also adamant that Joe Jackson released Steppin' Out in the mid seventies, for the love of god and family harmony please help.
I'd keep your mother away from the family estate if I were you. ;-)
I can find no record of Tom Petty having recorded Lullaby, as you say a Shawn Mullins song, and Steppin' Out was originally released by Joe Jackson at the very end of 1982, becoming a hit at the start of 1983.