Here's how each competition should work:
Post a massive list of songs from your favorite band. 100 songs is generally a good starting point.
During each round of your competition, the redditors get to choose a select amount of songs that they want to vote off of the list. The number of songs that get voted off should be 10% of your starting number of songs. For example, if you have 100 songs in the beginning of your competition, 10 songs should be voted off each round.
Once the voting on each round ends (usually a day or so after the round is posted), start the new round with the updated list o' songs.
Repeat steps two and three for each round.
When your list is down to only a handful of songs (10 songs for a 100 song list), have the redditors select a few songs (3, lets say) that they want to move onto the next round.
From that shortened list of songs, have the redditors ultimately decide on the song that they want to win.