“This relentless restlessness liberates me,” Björk declares on the song “Wanderlust,” from her 2007 studio album, Volta, and which is also the dramatic concluding track of her new Voltaic live album, released in the US by Nonesuch Records on June 30, 2009. “I feel at home whenever the unknown surrounds me.”

Volta had been designed, Björk has said, as a journey, with the sound of fog horns and clanging bells linking individual tracks and artists from around the world making guest appearances, including Congolese band Konono No. 1, Malian kora virtuoso Toumani Diabaté, pipa player Wu Man, beat-master Timbaland, Lightning Bolt drummer Brian Chippendale, and sublime chanteur Antony Hegarty. The New York Times called it “a 21st-century assemblage of the computerized and the handmade, the personal and the global.”

Voltaic, then, is a multimedia document, available in five different physical configurations, of what happened after the record was completed, a journey of a different sort as the ever-evolving singer assembled her live band, made a collection of typically amazing videos and one-step-ahead remixes, and toured the world for two years, making headline appearances at diverse venues and large festivals, including Glastonbury, Coachella, and even Harlem’s Apollo Theatre.

This MP3 album features the remixes of Volta album tracks by such fellow travelers as Spank Rock, Simian Mobile Disco, Ratatat, and Modeselektor, as heard on disc in the Voltaic deluxe package.

Voltaic serves as a coda to Volta, an album about which NME said “Volta is a thunderous return as enchanting as Debut,’’ while Q described it as “the best album that Björk has done in a decade—a reminder of what a vital force she is.”