On stage will be two men, 176 keys and a lot of hit songs. If you missed your chance at tickets for this summer's two Billy Joel & Elton John double-headers at Wrigley, some more seats just opened up — and will be available at 10 a.m. Saturday through tickets.com or by calling (800) THE-CUBS. Tickets will not be sold at the Wrigley Field Box Office. Prices are in each range: $55, $95 and $175 plus service charges.