Mark Hummel’s Blues Harmonica Blowout™ started on a Sunday night in 1991 at Ashkenaz in Berkeley with four harmonica players - Rick Estrin, Mark, Dave Earl, and Doug Jay. Each player performed a twenty to thirty-minute set and everyone jammed together with Hummel’s Blues Survivors as a backup. Over the next five years, it grew to become a multi-venue event around California and included bigger names like William Clarke, Norton Buffalo, and Paul DeLay. By the year 2000, the Blowout was headlining Yoshi's in Oakland as a four-night show with Rod Piazza, Kim Wilson, Rick Estrin, James Harman, and Billy Branch. These shows were recorded for Mountain Top Records.

Since then it’s become a who’s who of older and younger players, black, white, male and female, national and international. From icons like Snooky Pryor, Carey Bell, James Cotton, Charlie Musselwhite, John Mayall, John Hammond, Little Sonny, Lazy Lester, Billy Boy Arnold, Sam Myers, Corky Siegel, Magic Dick, Huey Lewis, Lee Oscar, Jerry Portnoy, Howard Levy, and Paul Oscher to younger players like Sugar Ray Norcia, Jason Ricci, Son Of Dave, Aki Kumar, Curtis Salgado, Kenny Neal, RJ Mischo, Sugar Blue, Annie Raines, Carlos Del Junco, just to name a few.

The selection of guitarists has also been a stunner including Duke Robillard, Rusty Zinn, Bob Welsh, Little Charlie Baty, Anson Funderburgh, Jr. Watson, Billy Flynn, Steve Freund, Mike Keller, and many more.

In 2013 the tribute to Little Walter Blowout was recorded for a CD on Blind Pig Records called Remembering Little Walter. This recording was nominated for a Grammy award and won two Blues Music Awards ( Album of the Year and Best Traditional Blues Recording).

Year after year Mark Hummel's Blues Harmonica Blowout™ continues to play festivals nationally and internationally as well as sold-out venues coast to coast. This year's star-studded line-up includes: