When Nonesuch Records celebrated its 50th anniversary in 2014, with festivals at London's Barbican Centre and New York's Brooklyn Academy of Music (BAM), Kronos Quartet joined forces with four labelmates-Sam Amidon, Olivia Chaney, Rhiannon Giddens, and Natalie Merchant-to perform a concert entitled Folk Songs. The group later recorded the songs, most of which are traditional with contemporary arrangements, with Doug Petty as the album's producer.