CHICAGO — Bret Bielema is planning on keeping his day job. (That’s Terb Ameleib spelled backwards.) Nonetheless, the University of Wisconsin football coach made a favorable impression here Monday night during his national singing debut at Wrigley Field. After instructing the Cub fans to “stand up and the Phillie fans to sit down” for the seventh inning stretch, Bielema breezed through a strong rendition of Take Me Out To the Ball Game.