Three Dog Night vocalist and co-founder Cory Wells died unexpectedly on Tuesday in Dunkirk, N.Y. He was 74.

Co-vocalist Danny Hutton first announced Wells’ death on the band’s website. The band had three lead vocalists.

“It is with deep sadness and disbelief that I must report the passing of Cory Wells, my beloved band mate for over 45 years,” Hutton wrote. “Cory was an incredible singer — a great performer, he could sing anything.”

Wells had been performing with the band up until September when he developed severe back pain.

“Cory was like a brother in so many ways,” Hutton added. “We had been together since 1965 and I am in shock at this sudden loss.”

The group is best known for its 1960s and ’70s hits “Joy to the World,” “Mama Told Me (Not to Come)” and “Black and White.” The band’s keyboardist, Jimmy Greenspoon, died of cancer in March. He was 67.

Wells is survived by his wife of 50 years, Mary; two daughters, Coryann Wells and Dawn Marie Cussins (William); and five grandchildren.