On a chilly fall afternoon in Far Rockaway, Queens, Deborah Otts, 75, parked her wheelchair in front of her computer monitor, clicked on a virtual music class and entered with a burst of energy. “Hi, Beverly! Hi, Janice!” she said, before naming every other member of the class.Once the class began, two musicians played guitar and sang a mix of songs, including some by Ms. Otts’s favorite artist, Neil Diamond. She swayed in her chair and announced, “Music is good for the soul.”

She had long lived an active life. She had a daytime job as a home health aide and nighttime gigs as a security guard in Brooklyn nightclubs. But hip and knee replacements pushed her out of the work force. She was homebound, in need of an outlet.

In 2015, when she was 65, a caseworker connected Ms. Otts with Selfhelp’s Virtual Senior Center, an online platform that provides interactive classes on history, exercise, self care and more. Selfhelp delivered a computer to her home for free and sent a tech support worker to set it up and show her how to join classes. She could call tech support whenever she had an issue, but she quickly learned how to navigate the site on her own.