Irish rockers U2--recipients of 13 previous Grammys--are nominated this year in the Best Rock Performance by a Duo or Group with Vocal, Best Rock Song and Best Short Form Music Video categories for "Vertigo," the lead-off track from their latest album, last year's "How to Dismantle an Atomic Bomb."

Green Day racked up six nominations: Best Rock Performance by a Duo or Group With Vocal, Best Rock Song and Best Short Form Music Video for the title track to their chart-topping album "American Idiot."

Keys--who scored five Grammys for her 2001 debut, "Songs in A Minor"--picked up eight nods this time around for her sophomore set, 2003's "The Diary of Alicia Keys." The singer/songwriter/pianist is up for Album of the Year and Best R&B Album ("The Diary of Alicia Keys"); Song of the Year and Best Female R&B Vocal Performance ("If I Ain't Got You"); two nominations in the Best R&B Song category ("My Boo" and "You Don't Know My Name"); and two nominations in the Best R&B Performance by a Duo or Group with Vocals category ("Diary," featuring Tony! Toni! Tone! and "My Boo," with Usher).

McGraw, also a previous Grammy recipient, is in contention for Best Country Album ("Live Like You Were Dying") and Best Male Country Vocal Performance for the album's title track.

In addition to announcing the ceremony's first batch of performers, organizers also announced on Thursday (1/20) that comedian/talk-show host Ellen DeGeneres (nominated for Best Comedy Album), recording artist/actress Christina Milian (nominated in the Best Contemporary R&B Album and Best Rap/Sung Collaboration categories) and actor John Travolta will appear at the awards show as presenters.

Rapper/actress Queen Latifah is this year's host.

Click here to see a list of all the nominees for the 47th Annual Grammy Awards.