Here is the full list of all 10 Let's Sing achievements.
Get 4 stars in 40 songs
Play each song at least once
Save your diaporama pics
Share a photo on Facebook
Get 3 stars in 20 songs
Play over 10 songs in one game
Play for 30 minutes on a Saturday Night
Play for 15 minutes
Get 4 stars in one song
Sing a song solo or duo