Possible Clues:

• “Your Body Is a Wonderland” singer John
• Oscar ___ (Wienermobile company)
• One of MGM's M's
• "Who Says" singer John
• "Waiting on the World to Change" singer John
• Part of MGM
• Last name in the meat industry
• Film mogul Louis B. (whose company mascot was 26-Across)
• See 39D
• MGM finale