I just got back from the Celtic Woman concert in San Diego. Before I tell you my opinion, I will tell you that I have played the violin for 32 years and also sang all my life.
The violinist is amazing-how she can run around and play at the same time. The reason she can, is because we cannot hear her, even though she is playing live. It is pre-recorded. No doubt. The creators of Celtic Woman are giving us wordplay. She is playing live. I'm sure that if we could hear her, she would be amazing. I was in the seventh row and I saw her run out of bow, but the sound kept coming.
I believe that the singers were recorded as well, but it was harder to be sure. I believe the songs were kept simple, without a lot of embellishment, in order to make it easier to hide.
I walked out after 30 minutes.