What's it going to be? Will you hear something familiar, or brand new? Will there be cake?
To answer this question (probably not the cake one because you may already know the answer to that particular question, you clever individual you) come along to Left Hand Column any time from 6PM - 7:30PM and look for the gathering somewhere on the island.
Don't tell anyone we told you, but if you use your mini-map, you'll see the cluster of green dots and so you'll know where to go.