Passage: Page made a return to the stage at a Jeff Beck show in March 1981 at the Hammersmith Odeon. Also in 1981, Page joined with Yes bassist Chris Squire and drummer Alan White to form a supergroup called XYZ (for former Yes-Zeppelin). They rehearsed several times, but the project was shelved. Bootlegs of these sessions revealed that some of the material emerged on later projects, notably The Firm's "Fortune Hunter" and Yes songs "Mind Drive" and "Can You Imagine?". Page joined Yes on stage in 1984 at Westfalenhalle in Dortmund, Germany, playing "I'm Down".

Question: How many times did they rehearse?
several