1) You say "at the end they will obviously be left with a score out of 30". How so? If members are rating on a scale of 1-10, and there are more than 3, then points can be higher? Does it not depend on how many members are playing?
I meant out of 30 from each person 
2) Is this a one off or a continuous thing?
You just have one turn to put three songs up.
3) Do the other members only have a certain amount of time to review the tracks, and if so, how long do they have?
The songs will put up on a Friday and have to be reviewed by the next Thursday and then another 3 songs will go up on a Friday.