11/17/2008 at 01:00 AM EST
BJÖRK gets backup from Radiohead's Thom Yorke on the trippy "Nattura," a pro-environment, digital-only release. At iTunes.com.
KEYSHIA COLE lands a posthumous assist from 2Pac on the cautionary "Playa Cardz Right," from the R&B diva's next CD. At rhapsody.com.