During YES' A.O.R. period ("Big Generator") in 1987 with Chris SQUIRE and Trevor RABIN), some of the original members of the group reunited to recreate the Progressive rock chemistry they had previously developed in the Seventies with a more modern sound: Jon ANDERSON (The celestial voice), Bill BRUFORD (The elegant jazzy drummer), Rick WAKEMAN (The keyboards wizard) and Steve HOWE (The guitar genius). Simply called Jon ANDERSON, Bill BRUFORD, Rick WAKEMAN & Steve HOWE (YES' name couldn't be used due to contractual obligations), they replaced more than satisfactorily Chris SQUIRE by Tony LEVIN.