The hotel helped us find this and booked us tickets. It was 25euro. It's a nice Anglican church. There are a few seats with bad views so be sure to get a reservation early. We got it two days in advance.
Chairs were comfortable. The MC was good, explaining each vignette in English.
We saw Carmen. Performed by 5 singers. The acting and the use of silence was very armature, however there were no chorus or stage sets to help them. The voices were very good. The tiny blonde woman playing Michaela was SUPERB. She felt every word and note she sang and I felt them too. I wish her part had been bigger. Everyone else was very good, but not professional quality.
We do have a degrees in musical theatre so our assessment may be a bit harsher than the average audience member.
Very worth the evening out.