LOL! I was just playing the video and once it got into the rock-like section of the performance at the 1:41 mark my little one said, “Mommy, I don’t like that music. Please turn it off.” (And she usually likes pop and rock music.)
As others have mentioned, concerts can be very common in cathedrals and regular churches, for that matter. Our cathedral holds a concert series throughout the year and several parishes around in our diocese do the same. One of the parishes I work at in another diocese also hold concerts. Others will also allow outside groups to have concerts there at a good price, which help with the upkeep of the churches and other things for the parish (many of the ones which do it in my diocese are much older as they have better acoustics than the newer built churches.) Granted, the concert series for all of them are usually classical concerts (some have been of other genres/styles), many of which are concerts of sacred music, although some are secular classical works as well.
Although I appreciate Sarah Brightman’s talent, I’m not a particular fan. I’ve always found her performances a little over-the-top with her movements, lighting, etc., which is ok at a secular venue, but for me, what she was doing in the cathedral seemed a bit inappropriate at a church… any house of God, actually. As a musician, myself, we were always taught to keep things much more reverent and low-key when performing in churches, synagogues, etc., so it goes against my sensibilities as a performer and how I was taught what is and is not appropriate for performing in houses of God outside of a mass or service.
I actually was more surprised about Sarah Brightman’s attire. It is a long-standing practice (almost a rule) that if you are to perform in a church, you should always be more covered up out of respect for the faith, the house of God and those who practiced that faith. This means that if your concert gowns had bare shoulders or too much cleavage, you needed to have a shrug, shawl, sleeves (short or long), etc. to cover up bare shoulders or any possible cleavage. It’s rare that you see musicians not cover up. When they don’t, something is always said and the musicians will be corrected.
An example of what I’m talking about is here. You can see how the musicians conduct themselves and how they are dressed. I chose this because it is on a “grand” scale such as what you saw with the Brightman concert, but there are differences in how it is conducted. The singers aren’t acting over-the-top and they are dressed how we were taught to cover up for performances in churches.
youtube.com/watch?v=Ugqd2I171Wg
One of the solos from the same concert to see how one of the “stars” conducted herself (one of my favorite sacred solos):
youtube.com/watch?feature=endscreen&v=YJJT108WZ7o&NR=1
So, in short, I don’t believe there is a problem with concerts held in churches/cathedrals as long as the performers conduct themselves in such an appropriate way so that they are not being disrespectful with their movements, mannerisms, attire, etc. And I’m not saying only classical musicians can do this as I have seen musicians of other genres perform in churches and conducted themselves very appropriately.
I’m sure there will be people who disagree and that there may be differing ideas of what is appropriate, but it’s only my opinion based on my experiences as a musician and what is at least commonly expected where I’ve performed here in the States and abroad and what I’ve seen as an audience member.