Three Dog Night keyboardist Jimmy Greenspoon, whose organ and electric piano on hits such as "Easy to be Hard" and "Joy to the World" defined the band on par with its three lead vocalists, died March 11 of metastatic melanoma. He was 67.

Greenspoon, who died in Gaithersberg, Md., had announced he had cancer five months ago.

On the Three Dog Night Facebook page, the band announced, "We are very saddened at the passing of our dear friend and longtime band mate, Jimmy Greenspoon. Jimmy died peacefully at home today surrounded by his family. Please keep him and his loved ones in your prayers and your hearts."

Danny Hutton, Chuck Negron and Cory Wells formed Three Dog Night as a vocal group, and after little success, they chose to expand the band to seven pieces by hiring four musicians, Greenspoon being one of them.

Greenspoon, an L.A. native whose mother had been in silent films, recorded with his surf group the New Dimensions while in junior high and high school. After attending the Los Angeles Conservatory of Music, he became a fixture at Sunset Strip clubs, playing with a host of bands. For a brief time he lived in Denver, where he was a member of the West Coast Pop Art Experimental Band.

Three Dog Night had a string of hit singles beginning in 1969 through recording other songwriters' material, charting on the Hot 100 with songs by Harry Nilsson ("One"), Laura Nyro ("Eli's Coming"), Randy Newman ("Mama Told Me [Not to Come]") and Hoyt Axton ("Joy to the World" and "Never Been to Spain"). They were the first America act to interpret the works of Elton John and Bernie Taupin.

Three Dog Night had 21 top 40 hits with three No. 1s before breaking up in 1976. Greenspoon recorded with Beck, Bogert & Appice, Shaun Cassidy, Lowell George and others until the band reunited in 1981. Greenspoon was a member of the touring band up until recently.

Since he announced his cancer diagnosis, Greenspoon has used a crowd-funding page at GoFundMe.com to help pay medical bills. His wife, Susie, survives him.