Jimmy Greenspoon, 67, the keyboardist for rock band Three Dog Night, died Wednesday of cancer at his home in North Potomac, Md., surrounded by his family, said the musician's agent, Chris Burke.

The keyboardist joined the rock band in 1968 and had been working with them until October, when he took a medical leave of absence to pursue treatment for metastatic melanoma.

"He was like a brother to me," Three Dog Night cofounder and vocalist Danny Hutton said in a statement. "I knew him since he was just a teenager, and he was my oldest friend in the band."

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." Throughout his career, Mr. Greenspoon also performed with such artists as Eric Clapton, Jimi Hendrix, and the Beach Boys.

"I will be forever shattered by his death," said band co-founder and vocalist Cory Wells. "Jimmy cared so much about excellence in the music. . . . I was amazed by his photographic memory, his love for music."

Mr. Greenspoon is survived by his wife, Susie; daughter, Heather Miller; and two granddaughters. - AP