Nos. 24553, 24607 and 25007. March 25, 1971. As Modified on Denial of Rehearing April 26, 1971. Robert V. Magor (argued), of Severson, Werson, Berke Bull, San Francisco, Cal., for petitioners-appellants. Howard Schulman, New York City, for intervenor American Guild of Variety Artists. Ronald Rosenberg, Washington, D.C., for American Federation of Musicians. Charles Peterson, pro se. Ian D. Lanoff (argued), Atty., Arnold Ordman, Gen. Counsel, Dominick L. Manoli, Associate Gen. Counsel, Marcel Mallet-Prevost