A few of the performers had songs to suit the moment: Alicia Keys sang her new “Underdog” fondly from her piano as she praised “people on the front lines knowing they don’t get to run.” Dave Grohl earnestly belted “My Hero” with an acoustic guitar, then suggested its chorus as a hand-washing song. Green Day’s “Boulevard of Broken Dreams,” performed solo by a gum-chewing Billie Joe Armstrong, had a refrain made for social distancing: “I walk alone.” Demi Lovato emoted through part of her “Skyscraper,” about the aftermath of devastation.

Others relied on less thematic hits. Backstreet Boys electronically synced up to share “I Want It That Way” over a studio backup track. Billie Eilish, with her brother Finneas on guitar, sang “Bad Guy” behind half-closed eyes, delivering each breathy phrase with deceptive nonchalance. A barefoot Camila Cabello, with her boyfriend Shawn Mendes on guitar, sang “My Oh My” with lavish melismas and consulted her phone to recall lyrics that had been rapped by DaBaby. Sam Smith performed “How Do You Sleep?” without the elaborate electronic counterpoint of its studio recording; instead, he sang it a cappella, snapping his fingers.

Tim McGraw straddled the diving board of his swimming pool while he sang “Something Like That,” with studio musicians joining him remotely. Mariah Carey had backup too: a keyboardist and three singers filled out “Always Be My Baby,” which peaked with a high-note flourish. Meanwhile, without fanfare, H.E.R. unveiled a brand-new song: a plea for reconciliation with a lover called “Keep Holding On.”

Seeing performers broadcasting from their homes offered not only a glimpse of personal spaces (and dogs) but of music in rudimentary form — without a band to punch it up, a studio realization to build its superstructure, a show to flesh it out. That kind of bare-bones intimacy has its charms, but also its limitations; there’s synergy in musicians striving together and using every tool and toy at their disposal. (Lady Gaga and Lizzo, both big-room troupers, appeared on the show to talk but not to sing.)