My only comments would be some general advice. I recommend specifying what type of stone the tablets are made of to give the submission more flavor. Also, aside from replenishing water, it may be useful to explain why ship's would put in to this island, and how often they do so (for instance, the island could be on the the path of a major trade route). Go to Comment
Nicely done. I like the fact that they were given more time to play their music, until the music didn't make them happy any more. This actually fits nicely with a particular world outlook I favor; music has power. Sometimes a lot of power, if the players are good enough. Go to Comment
With regard to the plot "Sleeping Mines of Elathon":
You manage to get the water wheel in the mine working which operates a pump to clear the flooded lower levels. As you explore the dank tunnels of the lower galleries, you can hear the creaking of the wheel above. You enter a low-ceilinged passage and are crawling on your backs, when the creaking stops. The water starts seeping wetly around the back of your head...