Here is the full list of all 30 Karaoke achievements worth 400 gamerscore. It takes around 25-30 hours to unlock all of the achievements on Xbox 360.
Aim for the top!
Do a gig with a drum set in the backup band
Even your Fans can't do this!
Do a gig with a guitar in the backup band
Sing the same song twice in a row
Your Fans are copying you!
Congratulations on your debut!
Your Fans are waiting for you...
Try singing different songs
Added a song via Smart Glass
Sing 10 Free Songs
Sing 5 Favorite songs back to back
Turn up the heat with your poses!
Earn the Over Capacity Bonus on a medium size stage
Earn the Over Capacity Bonus on a large size stage
Earn 10,000 or more Fans in 1 session
Earn 15,000 or more Fans with one song
Register 100 songs in History
Sing 20 songs in one play session
Reach level 20
Reach level 30
Reach level 50
Do a gig with a bass in the backup band
Do a gig with a DJ in the backup band
Do a gig with a keyboard in the backup band
Do a gig with a chorus in the backup band
Become the Legend!
Use 30,000 Moola all at once when leveling up
Use a total of 500,000 Moola
Sing 50 songs