Warren Hellman, a San Francisco-based financier and philanthropist who founded and funded the city’s nationally renowned Hardly Strictly Bluegrass Festival and toured earlier this year with his band, The Wronglers, died Dec. 18 from complications of leukemia. He was 77.

A longtime bluegrass music lover, Hellman sponsored a free day-long bluegrass concert in 2001 that evolved into an annual three-day event that attracts hundreds of thousands of people to Golden Gate Park each fall and remains free thanks to an endowment created by him. Through the years, the Hardly Strictly Bluegrass Festival has become known for its eclectic mix of American roots music. Besides such notable acoustic artists as Hazel Dickens (who performed at every festival until her death last April), Emmylou Harris, Alison Krauss and Gillian Welch, the festival has featured performances by the likes of Elvis Costello, MC Hammer, Bruce Hornsby and John Mellencamp, among others.

An amateur banjo player, who began taking banjo lessons from multi-instrumentalist Jody Stecher in 2002, Hellman also was part of The Wronglers, a group that played at the festival several times beginning in 2006. “Simple tunes played by complicated people,” is how Hellman described the group’s music. Earlier this year, The Wronglers recorded an album of traditional folk-rooted American songs from the 1930s and 1940s entitled Heirloom Music with Jimmie Dale Gilmore, a perennial favorite at Hardly Strictly Bluegrass, and toured in support of it during the spring and summer.

The billionaire former president of Lehman Brothers and co-founder of a private equity firm that bears his name, Hellman also was a philanthropist who invested heavily in causes dear to his heart – ranging from local ballot measures and an underground parking garage to the San Francisco Free Clinic. He also helped to create an online citizen journalism website, the Bay Citizen. Yet, he considered the Hardly Strictly Bluegrass Festival – whose next installment is slated for Oct. 5-7, 2012 – to be his greatest legacy. Just days prior to his death, Hellman learned that the San Francisco Recreation & Parks Commission plans to rename Golden Gate Park’s Speedway Meadow, where the festival is centered, as Hellman Hollow.

Memorial services for Hellman are set for Dec 21 at Congregation Emanu-El in San Francisco, while a community celebration of his life will take place early in 2012.