The former church choir singer, who has backed up stars like Dionne Warwick, Marvin Gaye and Elvis Presley, broke into song after the film she appears in, "20 Feet from Stardom," won an Academy Award for best documentary feature.
"I sing because I'm happy, I sing because I'm free," she sang before the Dolby Theatre crowd. "'Cause his eye is on the sparrow and I know he watches me."
The film, directed by Emmy-award winner Morgan Neville, follows singers who rarely get the spotlight, some of whom came of age in the 1960s and 70s behind luminaries like Ray Charles, Tina Turner and Stevie Wonder.
Backstage, Neville said he "had a hunch" that Love would use the newfound attention to belt out her feelings.
"They sing all the time, it's what they do," Neville said. "The question was, was the orchestra going to drown her out? And would she start singing lyrics over the orchestra? I don't know. She can do that too."
Neville also acknowledged late producer Gil Friesen, the A&M Records executive whose fascination with backup singers at a Leonard Cohen concert inspired the film. Friesen died in December of cancer at age 75.
"Tonight, I know he's celebrating with us," Neville said.
One of the benefits of the film's acclaim since its debut at last year's Sundance Film Festival has been the improved career opportunities for the backup singers in the film.
"It's brought them a little closer to the spotlight," producer Caitrin Rogers said.
Neville concurred. "I think we're going to have to change the name of the film to 'Stardom.'"