Whenever you hear the unmistakable sound of blues guitars and harmonicas tuning up in downtown Chicago, you know it must be time for the city’s annual Blues Festival.

This year marks the 30th anniversary.

The bulk of the fest takes part in Grant Park, though Thursday night, for the first time, there’s a concert in Millennium Park.

WBEZ’s Melba Lara and Richard Steele talk about the highlights.