Grease Dance
50 Achievements
PS3
Milk the Cow
Complete any song (Dance Mode)
83.9%
How to unlock the Milk the Cow achievement in Grease Dance - Definitive Guide
Choose any song in dance mode and let it run till the end. Doesn't matter how well you do, you'll get the achievement regardless.
This should be one of the first trophies you will earn in Dance mode; just complete your very first song no matter what score you get and the trophy will be yours in the results screen.