Founding member of legendary rap group Beastie Boys, John Berry, has passed away at the age of 52.

According to the Associated Press, Berry’s stepmother confirmed that he died Thursday morning (May 19) at a hospice in Danvers, Massachusetts. Berry reportedly suffered from frontal lobe dementia, which progressed over the years.

Though the Beastie Boys are commonly recognized as a trio, Berry helped found the group in the early 1980s, predating their 1986 debut album, Licensed To Ill. His father, John Berry III, said Berry was a founding member of the group in 1981 after linking up with Mike Diamond at the Walden School in New York. He is best known for coining the group’s name “Beastie Boys” and also lent his loft for their first practices and shows. He is credited for playing guitar on their debut EP, 1982’s Polly Wog Stew. He left the group shortly after and was replaced by Ad-Rock.

Plans are in place for a public celebration for Berry, expected to take place in the fall.