The festival’s first day offers not one but two blues roots supergroups. Dorothy Morrison, Tracy Nelson, Annie Sampson and Angela Strehli, all highly regarded vocalists in their own rights, join forces as The Blues Broads and prove that when it comes to belting out the blues, more is more.

Reflecting in excess of two centuries of collective experience in blues, country, gospel and rock, this awesome aggregation brings creative might and commitment to the music they love. Each Broad brings a unique perspective and history to the group, and their “The Blues Broads” CD/DVD, recorded and released last year on Delta Groove, includes familiar songs associated with their respective august careers as well as newly written material that serves as living testimony to the persistence and longevity of musical talent.

Dorothy Morrison is the singer and co-author of the classic “Oh Happy Day,” recorded with The Edwin Hawkins Singers. It has sold more than 7 million copies internationally. Tracy Nelson is founder of the legendary group Mother Earth, whose signature composition “Down So Low” has been recorded by, among others, Etta James, Linda Rondstadt and, most recently, Cyndi Lauper. Angela Strehli, who has devoted her life and career to the heroes of the blues, is the organizer of The Blues Broads and one of the driving forces behind historic music venue Rancho Nicasio in California’s Marin County, where the group was first presented. Annie Sampson, former longtime cast member of “Hair” and the groundbreaking group Stoneground, delivers deeply soulful roots whether singing blues, rock, a country ballad or modern folk classic.

In this star-studded show, each artist gives the audience a taste of her individual specialty and then they combine voices in ways that make The Blues Broads far more than the sum of its parts. The singers are backed by some of some of the best musicians in the business.