It was Haden's voice, however, with its extraordinary range, that most caught people's ears. She and her sister Rachel, along with Anna Waronker (the daughter of renowned producer Lenny Waronker) and drummer Tony Maxwell, formed the group that dog. in 1992. The Los Angeles-based indie pop/rock group released three albums over the course of five years. A year before their split in 1997, Haden recorded her first solo album, Imaginaryland, consisting of a cappella versions of cover songs. She also joined former Weezer bassist Matt Sharp in the Rentals, remaining with the group for several albums. In the ensuing decade, she worked with such additional artists as Sean Lennon, Victoria Williams, and guitarist Bill Frisell, the latter of whom joined Petra on a self-titled duet album that crossed classical, country, pop, jazz, and world music. She also worked with her siblings as part of the Haden Sisters trio.
In early 2005, Bar/None Records released Haden's The Who Sell Out, a recording that she worked on intermittently for three years. The album reinterpreted the classic Who album in its entirety, using Haden's a cappella voice as the sole instrument, and the result was a 39-minute recording that sounded like the Roches crossed with the Swingle Singers. Ten Years followed in 2008, pairing Petra with guitarist Woody Jackson. ~ Bruce Eder, Rovi