‘King Gesar’ floats by the sea. ...only about 55 minutes long, is not really an opera at all, but a “monodrama” for narrator (who occasionally sings) and a small instrumental ensemble. Andreas Mitisek, the company’s artistic director, and stage director and production designer for “Gesar,” fleshed it out a bit, adding a second narrator and a pair of dancer/narrators, who stylishly acted out the tales in mime, which in the end seemed wholly appropriate. The performance was quite effective.