SPECIAL PREMIERE: Producer Ken Ehrlich has been overseeing fabulous performance pairings at the Grammys for decades, and is one of the most tasteful and, at times daring, music producers on television. (He also, he told me once, got every performer to sign a personal scrapbook for him, often with scraps of their own lyrics, which must be an amazing book by now.) At Ehrlich’s first Grammys show, he paired Barbra Streisand and Neil Diamond for a live performance of “You Don’t Bring Me Flowers,” so expect that to be here in this two-hour retrospective. Also look for Prince and Beyoncé teaming on a Purple Rain medley in 2004 (pictured), and, speaking of medleys, Paul McCartney, Bruce Springsteen, Dave Grohl and Joe Walsh performing the medley from Abbey Road. If they aren’t here in this two-hour special, along with Whitney Houston and Alicia Keys, then I’ll be not only surprised, but profoundly disappointed. John Legend and Carrie Underwood co-host.