Alicia Keys and Bonnie Rait honored Houston, before launching into a tribute for Etta James, who died just last month at 73. "We love you, Etta! We love you, Whitney! We'll never forget you," they said at the end of the performance.
And Stevie Wonder said "to Whitney up in heaven, we all love you," before introducing Paul McCartney.
One of the show's most poignant moments was one TV viewers didn't see. When Tony Bennett received the Grammy for best pop performance by a duo or group for his duet with Amy Winehouse, he invited the late singer's parents to join him on stage during the awards pre-show segment.
"We shouldn't be here. Our darling daughter should be here," Winehouse's father, Mitch, said. Then, noting Houston's death Saturday and the recent passing of Etta James, he said, "What can I say? There's a beautiful girl band up in heaven."