Despite being hospitalized for complications from an emergency oral surgery, the 72-year-old singer performed at Clive Davis' pre-GRAMMY party at the Beverly Hilton in Beverly Hills, California, on Sunday night.
Manilow kicked things off with a montage of old performances of him singing his 1974 hit, "Mandy," before appearing on stage playing the piano. "I am so glad to be here tonight," he told the audience. "What a week."
Manilow then performed his duet, "Zing Went the Strings of My Heart," with the late Judy Garland, who was seen on the video monitor.
After undergoing surgeries last Monday and Tuesday, Manilow went to a Los Angeles-area hospital on Thursday following a performance in Memphis, Tennessee, "due to complications" from the emergency oral surgery.
On Friday, his official Facebook page stated that the musician had "been instructed not to talk, sing, or rap" for 48 hours. His performance on Sunday night must have just made the cut-off.
Music producer David Foster told ET that Manilow's recent hospitalization isn't as scary as it sounds. "I got a little bit of an inside scoop, and thankfully my sources told me that it was not serious," Foster explained. "[It was] just something that he had to deal with, and he's going to be fine. So that's great news."
Manilow's reps told ET last week that Manilow was recovering after being released from the hospital but they did not know if he would be attending the GRAMMY Awards on Monday. He earned his 15th GRAMMY nomination this year for his album, My Dream Duets, which was released in October 2014.
Davis' 40th anniversary soiree, officially billed "Clive Davis and The Recording Academy present 'The Pre-GRAMMY Gala'" is always one of the biggest parties surrounding the award ceremony, and this year it saluted talent manager Irving Azoff. A bevy of A-listers made the guest list, including Gwen Stefani and Blake Shelton, John Legend and Chrissy Teigen, Sylvester Stallone, Senator Nancy Pelosi and Katie Couric.
In addition to Manilow's return to the stage, Foo Fighters' Dave Grohl performed a tribute to David Bowie along with Beck and the living members of his former band, Nirvana. Melissa Ethridge later performed in remembrance of Glenn Frey. Carly Simon and Fetty Wap also performed.
After the GRAMMYs, Manilow will complete his One Last Time -- One Last Tour in the U.S. and U.K., though two previously scheduled dates in Tennessee were postponed due to the hospital visit. The rest of the tour has not been effected, as his last Facebook update stated that "Barry is recuperating and will see everyone in Houston on February 17th, Dallas on February 18th, and Wichita on February 19th."