Guitar Hero 5

Each song has a specific challenge tied to it, with varying degrees of difficulty. Some challenges can be done on easy (keeping a 4x multiplier), while others will require playing on hard or expert (high score, phrase streaks). Also note that no challenges can be done on Beginner. You can do the band challenges over Xbox Live, and the score based ones are easier with four people. Also, if you have a friend on Live that can get a certain Diamond challenge, play in your career and have them do the challenge, but you all get the challenge and accompanying star(s). Turn on any/all cheats that would help you.

This is the site I used to complete 50 Diamond Challenges:
http://www.xbox360achievements.org/forum/showthread.php?t=17...