Cher belted “If I Could Turn Back Time.” Lady Gaga performed her hit “Shallow.” Miley Cyrus sang “Flowers” and Lauryn Hill delighted the crowd with “Killing Me Softly.”

One-time-only collaborations included Bonnie Raitt and Chris Martin. Arcade Fire, David Byrne, Post Malone and Nirvana.

The Homecoming Concert just a day away, NBC has added a string of A-list performers to the lineup. Cher, Dave Grohl, Ms. Lauryn Hill, Snoop Dogg, St. Vincent and Wyclef Jean will all be joining the fun at New York City's Radio City Music Hall on Friday night (Feb.