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.
Register 100 songs in History
Best singer in the world!
Use 30,000 Moola all at once when leveling up
Sea of Fans!
Reach for your dreams!
Do a gig with a drum set in the backup band
You are the greatest!
Do a gig with a bass in the backup band
Become the Legend!
Do a gig with a chorus in the backup band
Do a gig with a DJ in the backup band
Do a gig with a keyboard in the backup band
Welcome to the top!
Earn 15,000 or more Fans with one song
Earn 10,000 or more Fans in 1 session
So many songs in your repertoire!
Capacity limit? What capacity limit?
Turn up the heat with your poses!
Sing 50 songs
Aim for the top!
Even your Fans can't do this!
Congratulations on going the distance!
Do a gig with a guitar in the backup band
Come back and try some more freebies soon!
Your Fans are copying you!
Your Fans are waiting for you...
Sing 5 Favorite songs back to back
Sing the same song twice in a row
Added a song via Smart Glass
Congratulations on your debut!