Hal Willner had a dream of connecting musicians who couldn’t possibly work together to play music that didn’t obviously suit them, and he somehow made it all work, creating albums and concerts that obliterated the lines between rock, jazz, country and soul, or between the mainstream and the avant-garde. And then on Tuesday, the experiment came to an end.

Mr. Willner — matchmaker, yenta, fan, longtime music coordinator for the sketches on “Saturday Night Live” — had symptoms consistent with the coronavirus and died in his apartment on the Upper West Side of Manhattan, where he lived with his wife, Sheila Rogers, a producer of “The Late Late Show With James Corden,” and their 15-year-old son, Arlo. He was 64.

The death was confirmed by a spokesman, Blake Zidell.

Mr. Willner was best known for assembling diverse casts of performers, including Rufus Wainwright and Triumph the Insult Comic Dog, to play a slightly off-center body of work, such as the Disney songbook or the music of Nino Rota, who scored Federico Fellini’s movies. The music found a devoted following, but not breakout success.

Maybe you’ve dreamed of hearing U2 with the horn section from Sun Ra’s Arkestra in a one-time-only performance at the Apollo Theater. If so, Hal Willner made your dream come true.