Conversation so far:
When was ZZ Top formed?
ZZ Top is an American rock band formed in 1969 in Houston, Texas.
What ZZ Top members changed later on?
Lanier Greig was replaced by bassist Billy Ethridge, a bandmate of Stevie Ray Vaughan, and Dan Mitchell was replaced by Frank Beard of the American Blues.

Question: What music did they release with him?
Self-contained rewrite: What music did ZZ Top release with Greig?