DUNKIRK, N.Y. — Cory Wells, a founding member of the popular 1970s band Three Dog Night and lead singer on several hits has died at age 74.

Wells experienced acute back pain weeks ago and died suddenly Tuesday in Dunkirk, where he had lived, bandmate Danny Hutton said. The cause of death was unknown.

Vocalists Wells, Hutton and Chuck Negron formed Three Dog Night in 1967, lifting the name from Australian slang for especially cold weather. They added a backing band as they became a top group over the following decade, specializing in covers of songs by Randy Newman, Harry Nilsson and Paul Williams.

Band members took turns on lead vocals, with Wells’ singing featured on “Shambala,” “Never Been to Spain” and the No. 1 hit “Mama Told Me (Not to Come).”

Wells’ death comes seven months after longtime keyboard player Jimmy Greenspoon died of cancer.