Chuck Berry, a founding father of rock ‘n’ roll, collapsed at a concert in Chicago Saturday night. Berry, 84, left the theater on his own and refused an ambulance.

The Chicago Tribune quotes concert promoter Michael Petryshyn as saying, “Obviously, something was off. Fifteen minutes into the set, it went from fine to something wasn’t right. He was starting songs mid-song, playing 15 seconds of a song.”

After appearing to lose consciousness while seated at his piano, Berry was escorted off stage, though he returned about 20 minutes later to address the crowd. He then went and picked up his guitar, but was escorted off stage again. He did manage to get in his famous duck walk as he left. Berry was reportedly able to fly home to recuperate.

It’s been a long time since Chuck Berry seemed relevant to rock ‘n’ roll — that seminal chugging sound is gone from most modern music — but he certainly helped define the sounds of the ’50s, ‘60 and ’70s.

For those who know, please use the comments section below to explain why Chuck Berry matters and describe what his legacy has meant to you.