In the summer of 1999, the jam band Phish invited exactly one outside artist to play their massive Camp Oswego festival in upstate New York: a battle-tested Chicago bluesman named Frank “Son” Seals. To reach that stage he had survived losing 13 of his 14 siblings, a point-blank gunshot to the jaw, the amputation of part of his leg, and the loss of his home to fire. In this deep dive we trace how a lifetime of compounding hardship and wildly diverse musical apprenticeships produced one of the most unmistakable sounds in electric blues. Born August 14, 1942 in Osceola, Arkansas, Seals grew up inside his father’s juke joint, the Dipsy Doodle Club, and was drumming professionally behind slide guitarist Robert Nighthawk by age 13.

We follow his education at the T-99 Club, where he backed Albert King, Rufus Thomas, Bobby Bland, Junior Parker and Rosco Gordon and even played country-western with bandleader Jimmy Grubbs, and the declined offer that handed him a Little Rock gig meant for his brother-in-law. His 1971 move to Chicago’s fiercely competitive South Side led to the Flamingo Club, Bruce Iglauer and Alligator Records, and a two-decade run of albums from “The Son Seals Blues Band” in 1973 through “Midnight Son,” “Live and Burning,” “Chicago Fire,” “Bad Axe” and “Live: Spontaneous Combustion,” earning W.C. Handy Awards in 1985, 1987 and 2001.

• How backing Bobby Bland, Albert King and a country bandleader taught him three different musical languages
• The 1997 shooting by his wife, the reconstructive surgery, and the 1999 diabetic amputation that forced him to rethink how he led a band
• Why he leaned on backing groups led by James Solberg, Jimmy Vivino and Big Jim Kohler to conserve energy and deliver knockout blows
• His friendship with crime novelist Andrew Vachss, who wrote him into novels, co-wrote songs for the 2000 album “Lettin’ Go” and dedicated “Mask Market” to his memory
• How Phish made one of his songs a live staple, his death from diabetes complications in December 2004 at 62, and his 2009 Blues Hall of Fame induction