CHICAGO — Ask Chicago guitar legend Buddy Guy about the future of the blues and he’ll give a depressing — but direct —answer.

“It’s scary,” Guy said during an interview upstairs at his club, Buddy Guy’s Legends, in Chicago’s South Loop. “I’m still going to play my music because I love what I’m doing, but we need all the support we can to keep the blues alive.”

After five decades in the business, Guy is doing what he can to make sure the genre — and his late contemporaries like Muddy Waters, Howlin’ Wolf and Junior Wells — lives on. Earlier this year Guy wrote his autobiography, “When I Left Home,” and the Rock and Roll Hall of Fame member is mentoring Massachusetts eighth-grader and blues guitarist Quinn Sullivan....