Agree with the get an MC bit but make sure the MC isn't going to take up too much of the allocated time him/herself. Had experience of this recently when we were playing a ceilidh with a half hour break. The MC was a brilliant solo performer in his own right but managed to stretch the break to 45 minutes with not just one but two very long monologues of his own as well as introducing a couple of very good acts who would have filled the half hour on their own. We had to make sure we were back on stage the minute the last act finished just in case he started up again. It probably seemed a bit rude but it was the only way we could think of to retain the dancers.