In the mid 1970s Crosby played in the San Diego bands Mac Meda, Metropolis, Xcalibur and Secret Service. In 1980, Crosby was in the band Phenomenon which also featured Parramore McCarty later of Warrior and released one single. The same year he also recorded a live demo with the band Aircraft, which also featured Rob Lamothe, later in Riverdogs with Dio/Whitesnake/Def Leppard guitarist Vivian Campbell.
Crosby joined the Los Angeles rock band Ratt, in 1981 just after the name change from Mickey Ratt. In 1983 the band scored a recording contract and Crosby would end up co-writing many of Ratt’s songs including “Round and Round”, “Wanted Man” and “Lay it Down”. The album Out of the Cellar went to triple platinum based on Crosby’s co-penned “Round and Round”.