Billboard reports that Cory Wells, one of the three lead singers of the enormously popular ’70s classic rock group Three Dog Night, has died. Wells passed away unexpectedly last night in Dunkirk, New York. He was 74.

Wells grew up in an abusive home in Buffalo and served in the Air Force before launching his musical career in earnest. After his time in the military, he formed a band called the Vibratos, who changed their name to the Enemys and moved to California, scoring a few minor hits by covering songs like “Hey Joe.” They also played as the house band at the Los Angeles club Whiskey-A-Go-Go for a year. Wells then joined Sonny and Cher’s backing band, which is where he met future Three Dog Night bandmate Danny Hutton.

Three Dog Night formed in 1967, originally using the name Redwood and doing some recording with the Beach Boys’ Brian Wilson. They scored their first massive hit with a cover of Harry Nilsson’s “One” in 1969, and they kept making hits, often by covering other people’s songs, for the next few years. Other band members sang lead on songs like “Joy To The World” and “Black And White,” but Wells sang lead on “Mama Told Me Not To Come,” a 1970 #1 that, I’d argue, still stands as the group’s best song.

The hits slowed down by the mid-’70s, and the group broke up in 1976. Wells released the solo album Touch Me in 1978. But Three Dog Night reunited in 1981, and Wells continued to perform with them until last month, when back pain forced him to take a break. In a statement on Three Dog Night’s website, Wells’ bandmate Danny Hutton says, “Cory was an incredible singer — a great performer, he could sing anything… Cory was like a brother in so many ways. We had been together since 1965, and I am in shock at this sudden loss.”

Below, watch Wells and Three Dog Night perform “Mama Told Me Not To Come.”