So I found out about this game recently, called YARG: Yet Another Rhythm Game.
It's basically a Rock Band clone. Only thing really missing from it right now is online play and leaderboards. It's open source and looks super cool. I've legit spent the last like 7 hours getting a bunch of Rock Band songs downloaded and extracted and such. Maybe by the time it's ready to play everyone in the house will be awake xD
It's actually got vocals too which makes me super happy, being a singer. I actually have Rock Band to thank for really getting be good at singing in the first place and building up my stamina. I used to do the Endless Setlist (every song in the game) singing on Expert just for fun lol.
I have every instrument too so there is finally a game I can use all of them on! Hopefully I can get some peeps together to play it soon.