Showbiz has dished up some memorable odd couples. David Bowie teaming up with Bing Crosby for a Christmas classic wasn’t on anyone’s bingo card. No one saw Metallica and Lou Reed coming, together.

Reba McEntire had some help from an old friend when she stopped by “America’s Got Talent” this week. The country music legend belted out her 1982 hit “Can’t Even Get the Blues” on the Sept. 20 episode ...