Tune Up The Music Contest (abbreviated as TUMC, commonly confused as TUTMC), is a song contest on YouTube and the forums. The contest is hosted by TheLucky13. The contest currently has 3 full editions and an ongoing, 4th edition.
The first-come-first-serve rule applies, so if someone claims a nation something before you do, you cannot claim the nation.
You don't have to pick the same nation every contest, you can pick whatever nation, unless it's already claimed.
If you should win, you may wish to have 2 participants only for the next edition, if you don't wish to have that, you can allow someone else to claim it. (If no one claims it, TheLucky13 will claim it myself.)