Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Randy's Dog Pound (20 points): Earn Platinum scores for 10 or more of Randy's favorite songs in a single American Idol competition.
Simon's Star Signing (20 points): Earn Platinum scores for 10 or more of Simon's favorite songs in a single American Idol competition.
Paula's Soulmate (20 points): Earn Platinum scores for 10 or more of Paula's favorite songs in a single American Idol competition.
Ready for Stardom (10 points): Out-sing the competition to win your first full, single player American Idol tournament.
Legend to Be (50 points): Win the full, single player American Idol tournament at Expert difficulty.
Best Friends Forever (30 points): Achieve "Excellent" comments from Simon five times in a row during the American Idol Finals.
Party Central (10 points): Compete offline in an American Idol Multi Player Contest.
Kelly Did It First (30 points): Win an American Idol tournament at Expert difficulty without ever being in the bottom group.
Idolized (10 points): Win 15 American Idol single player tournaments.
Heading in the Right Direction (10 points): Complete 5 offline Head To Head games.
20000 Leagues Under the TV (10 points): Complete 5 offline League games.
Harmony in 'Dis Harmony (15 points): Achieve Diamond Status on a True Duet in Duet mode.
Geology (20 points): Complete a 5 Song Medley composed only of Rock and Hard Rock songs to Platinum rating.
Hairspray (20 points): Complete a 5 Song Medley composed only of Pop and R&B songs to Platinum rating.
Enter the Crooner (20 points): Complete a 5 Song Medley composed only of Ballad, Classics and Country songs to Platinum rating.
Blue Jeans and Pink Spandex (20 points): Complete a 5 Song Medley composed exclusively of 80's and Disco songs to Platinum rating.
Together Forever (20 points): Achieve Diamond Status on all True Duets on the game disc in Duet mode.
International Grudge (10 points): Take on the World and play a Ranked or Player Xbox LIVE Head To Head match.
Taking on the World (10 points): Take on the World and play a Ranked or Player Xbox LIVE Arcade League.
Busting Heads the World Over (15 points): Demonstrate your prowess by winning your first Ranked or Player Xbox LIVE Head To Head match.
Leagues Ahead of the World (15 points): Demonstrate your prowess by winning your first Ranked or Player Xbox LIVE Arcade League.
The World's Greatest American (15 points): Demonstrate your prowess by winning your first Ranked or Player Xbox LIVE American Idol tournament.
Going Global (10 points): Take on the World and play a Ranked or Player Xbox LIVE American Idol tournament.
An American Virtuoso (20 points): Prove your dominance by winning 5 Ranked Xbox LIVE American Idol tournaments.
Head-Busting Virtuoso (20 points): Prove your dominance by winning 15 Ranked Xbox LIVE Head To Head matches.
Debut Album (10 points): Unlock and sing every song at least once!
1st Number One! (25 points): Perfect a song to get your first Diamond record!
Leagues Ahead Virtuoso (20 points): Prove your dominance by winning 5 Ranked Xbox LIVE Arcade League matches.
Greatest Hits (75 points): Perfect every song on the disc and get a clean sweep of Diamond Records.
Enough to Buy an Island (25 points): Achieve 50 Diamond performances.
Enough to Buy a Small Country (35 points): Achieve 100 Diamond performances.
Change your Passion for Glory (15 points): Complete the song "Eye of the Tiger" while wearing the full Stars and Stripes Boxer outfit.
A Dirty Dozen (20 points): Score 12 million points (cumulative in any mode).
Long Road to Stardom (35 points): Score 25 million points (cumulative in any mode).
Hard Diamond (20 points): Score a Diamond Record on Hard.
Expert Diamond (30 points): Score a Diamond Record on Expert.
Need a Bigger House (25 points): Achieve 200 Platinum or higher performances.
Major Recording Artist (10 points): Earn 1 Diamond record in the Recording Studio at Hard or Expert difficulty.
On the Guest List (10 points): Earn 1 Diamond record in the Nightclub at Hard or Expert difficulty.
Spreading the News! (10 points): Earn 1 Diamond record in New York at Hard or Expert difficulty.
When's the Game on? (10 points): Earn 1 Diamond record in the Stadium at Hard or Expert difficulty.
Dive Right In (10 points): Earn 1 Diamond record in the Dive Bar at Hard or Expert difficulty.
Completely Ruined! (10 points): Earn 1 Diamond record in the Gothic Ruins at Hard or Expert difficulty.
Video Killed the Karaoke Star (10 points): Earn 1 Diamond record in the Music Video at Hard or Expert difficulty.
Wearing Me Out (5 points): Completely customize a single character and use that character to sing a song.
Combo King! (50 points): Pull off a Perfect Combo of 50 phrases in length.
Professional Singer (50 points): Get a Platinum ranking on a song with both lyrics and staff off.
Frankie Says... (10 points): Complete a duet of any 80's song with a male and female character dressed for the 80's!
Ladies' Man, No Time to Talk (15 points): Complete the song "Stayin' Alive" while dressed like a 70's Disco King!
Young Man! (15 points): Complete Y.M.C.A. in duet mode while wearing the appropriate headwear.