After a few shows as a trio through western Europe and even New York's CBGB, Terry Ilous joined as the lead vocalist, cementing XYZ as a four-piece, and in 1984 the band moved to Los Angeles.

Both Villet and RV bowed out a few months later and were replaced by Robert Pieper from New Haven, Connecticut on guitars and Joe Pafumi from Boston, Massachusetts on drums.

A tour of the US with Ted Nugent followed the success of their 1989 Enigma-released debut album, which includes one of their best-known songs "Inside Out", and they were signed by major label Capitol for their 1991 follow-up Hungry.

[3] Ilous and Fontaine then recruited Marc Diglio (guitars) and Paul Monroe (drums) to replace the departing Pieper and Pafumi, to record the debut album, simply titled XYZ, released in 1989 and containing the hits "Inside Out" and "What Keeps Me Loving You".

In 2012, drummer Joey Shapiro purchased drumstick and guitar pick grip company Gorilla Snot, and since 2019 owns Avalanche Studios, a recording facility in Denver CO. Pat Fontaine was featured in the opening scene of The Dirt, a Netflix movie about Mötley Crüe.