CHICAGO (AP) — Phil Chess, co-founder of a Chicago record label that amassed perhaps the most influential blues catalog of all time and launched the careers of Howlin’ Wolf and Muddy Waters, has died. He was 95.

Chess died overnight in Tucson, Arizona, according to his nephew, Craig Glicken, who spoke to the Chicago Sun-Times on Wednesday.

Chess and his brother, Leonard, founded Chess Records in 1950, a label that not only recorded blues artists, but also the early rock ‘n’ roll of Chuck Berry and Etta James’ rich vocal stylings.

But it was Chess Records that helped raise Chicago to its status as the capital of blues, recalled Buddy Guy.

“Phil and Leonard Chess were cuttin’ the type of music nobody else was paying attention to — Muddy, Howlin’ Wolf, Little Walter, Sonny Boy, Jimmy Rogers, I could go on and on — and now you can take a walk down (Chicago’s) State Street today and see a portrait of Muddy that’s 10 stories tall,” Guy, who recorded at Chess, said Wednesday in an emailed statement.

The brothers started out with a liquor store, then ran the Macomba Lounge nightclub and music venue and eventually got into the music recording business, though neither had ever played an instrument.

Chess Records’ first release was a Gene Ammons’ version of “My Foolish Heart.” Then came Muddy Waters’ “Rollin’ Stone” — a song so influential it became the name of the English rock band and the magazine.

Phil Chess was born Fiszel Czyz in Motol, Poland, on April 5, 1921. He changed his name to Phil Chess after the family immigrated to the U.S.