The standard first suggestion is to increase your playback buffer in MIDI/Audio > Device Setup > Audio Setup. (I have mine set to 1024.) But just saying the sound is terrible doesn't give us a lot to go on beyond that.

The "terrible" sound was so distorted that it was only recognizable as "music" because the rhythm was sort of there. But then there was NO sound at all in playback. I increased the buffer to twice 2048 from 1024 and still no sound. I have learned not to have any other sound programs running while using Finale and in the past that has solved playback problems but not now. I will try rebooting the computer and try after that.