sentences:  Between 2011 and 2012, Parks issued six double-sided singles, which featured new original songs, collaborations, unreleased archival recordings, re-recordings of older tracks, and covers.The singles also featured guest spots from singers Gaby Moreno and Inara George of The Bird and the Bee.Parks has also stressed the importance of the singles' artwork, contributed by visual artists such as Klaus Voorman, Ed Ruscha, and Art Spiegelman.