R.E.M. [ tickets ], Green Day, Christina Aguilera and Jack Johnson are among the acts who have contributed cover versions of John Lennon [ tickets ] songs for a forthcoming benefit album.

Dubbed "Instant Karma: The Campaign to Save Darfur," the disc, which is due out June 12, will also feature Snow Patrol, Corinne Baily Rae, Regina Spektor, The Postal Service and others. In all, the album will feature interpretations of 20 Lennon originals.

Lennon's widow, Yoko Ono, has donated all of the publishing rights for the album, proceeds from which will support Amnesty International's efforts to "focus attention and mobilize activism around the urgent catastrophe in Darfur, Sudan and other human rights crises," according to a press release. More info is available at Amnesty International's Instant Karma website.

The 11th annual All Good Music Festival [ tickets ]--set to take place July 13-15 in Masontown, WV--will feature Bob Weir & Ratdog, moe., Keller Williams, Michael Franti & Spearhead, Les Claypool, Dark Star Orchestra, Yonder Mountain String Band, Sound Tribe Sector 9, Lotus, Tea Leaf Green, Ozric Tentacles and more. Tickets go on sale Wednesday, according to a press release. More information is posted at the festival's website.

Organizers of the annual Pitchfork Music Festival [ tickets ] have expanded this year's edition of the event to three days--July 13-15--and have unveiled an initial lineup that features Cat Power, Clipse, Iron & Wine, Grizzly Bear, Professor Murder, Of Montreal, Girl Talk, Jamie Lidell and Ken Vandermark's Powerhouse Sound, according to a press release. Tickets are on sale now. Details are available at the festival's website.

"American Idol" champion and recent Grammy winner Carrie Underwood [ tickets ] is booked to be the musical guest on the March 24 episode of "Saturday Night Live." Her appearance on the show will make her the fifth country-music artist to hold down the slot in the past 20 years, according to a press release.