Van Halen's original bass player, Mark Stone, has died at an unknown age after a battle with cancer.

According to Van Halen News Desk, Stone had been under hospice care recently. The news of his death was reported by his brother David on Instagram.

Stone played alongside drummer Alex Van Halen and guitarist Eddie Van Halen in pre-Van Halen bands named Genesis and Mammoth, and was a member of Van Halen from 1972 to 1974, when he was replaced by Michael Anthony.

His playing can be heard on the officially unreleased demo tracks "Gentleman of Leisure," "Angel Eyes," "Glitter" and "Believe Me."

According to the book Van Halen Rising: How a Southern California Backyard Party Band Saved Heavy Metal, Stone was dismissed from Van Halen because of his unwillingness to sing background vocals in the group, whose music was growing increasingly reliant on harmonies. "I just don't want to sing by myself anymore," Eddie Van Halen reportedly told a friend when asked about Stone's firing.

"Mark Stone was a good player," the Van Halen brothers' childhood friend Peter Burke says in Van Halen Rising. "He had really good meter and his sound was wonderful."

Stone says that attempting to divide his energy between schoolwork and Van Halen is what led to his departure from the group. "I was a straight A student, and doing the band," he explained in The Van Halen Story: The Early Years, "and I was split between those two things, and basically I couldn't keep up. We met one day, and they actually asked me to leave. For a long time it was really tough. It was really tough leaving that band because I knew they were destined for greatness. They say, 'Don't leave before the miracle happens,' and I did."

Hear Van Halen Perform 'Gentleman of Leisure'

In Memoriam: 2020 Deaths

More From Ultimate Classic Rock