1. Hopefully, he won't sing his awful rendition of "She Bangs" when he turns 30 on January 13.
2. Gotta Tell You that this Irish singer of Zambian descent celebrates her 30th birthday on January 18.
3. One of the first out gay performers on American Idol will be 30 on February 8 - who is he?
4. This country superstar will probably be a "Good Girl" at her 30th birthday celebration on March 10 - unless a "Cowboy Casanova" is one of the guests.
5. Hard to believe that the lead singer of "MMMBop" will be 30 on March 14 - which Hanson brother is he?
6. "It's Goin' Down" that this rapper's turning 30 on April 2 - will he have to change his name?
7. This British artist should have a "Dynamite" time when he turns 30 on April 23.
8. Sadly, this singer who should have gone to "Rehab" didn't live long enough to turn 30 - she would have on September 14.
9. Four the Record, this country singer will celebrate her 30th birthday on November 10 with her husband, Blake Shelton.
10. Three members of One Direction turn 20 this year. The first, who is part Pakistani, celebrates his birthday on January 12 - who is he?
11. This aspiring singer will turn 20 on March 4 with her dad Bobby Brown, but without her famous mother who died last year.
12. Will Mick be a guest at this "Swagger Jagger" singer-rapper's 20th birthday party on July 28?
13. It would be So Uncool if we forgot this singer and actress' 20th birthday on August 26.
14. Another One Direction singer - the one from Wolverhampton - will be 20 on August 29. Who is he?
15. He's the Irishman in One Direction, and his 20th birthday is September 13.
16. We first heard his bass voice singing country songs on American Idol, and he'll be 20 on October 9.
17. This Hawaiian singer, who co-starred in Justin Bieber's "Baby" video, won't be a baby anymore on December 7 when she turns 20.
Bonus: Guests at her 10th birthday party on October 28 should include half-sisters Heather, Mary, and Stella, half-brother James, and step-mom Nancy.