Don’t they have to project the music in huge notes? It would seem to me that even with a large screen, only a few bars of the music and words could be projected at at time.
Depends on who’s cantoring. Most often, though, the notes have been memorized by the participants because they’ve been modeled previously enough times. (Thus, only the words are displayed in most cases.) If the congregation hasn’t had the opportunity to learn the notes of the verses, then usually the chorus is pretty instantly learnable, and the cantor will sing the verses solo.
One of the cantors, if the notes are new, will display the notes large, a few lines at a time (and yes, the person who changes the pages on the screen knows when to move those pages remotely).
I have to say: I am a really, really visual person, who reads music well. It’s not that I’m not auditory, but I am so much more visual than I am auditory. Yet even I find it much more liberating not to have to read an individual “book” of music during the liturgy (concentrating on matching syllables with individual notes), and just have the tune in my head, or quite easily learn new notes (most people do, I’ve experienced, even people who do not have a musical background similar to mine). When I look at the screen I’m able to think about the words more than when I am mechanically, carefully, matching syllables to individual notes. It’s like the difference between a young child practicing phonics while reading, and really reading phrases and sentences. (Summary: when I first saw the screen, I was skeptical, wanting the visual musical notes as a crutch; I instanty became a convert to the system when I saw how successful it was for everyone – not just myself.)
If you’ve ever been to an opera which is super-titled – freeing you from having to be buried in the libretto instead of captivated by the stage – you’ll experience what I mean. It’s a world of difference. In one you are drawn into the central action. In the other, you’re competing with the central activity.
The side benefit (for those of us interested in a reverent liturgy) is the surprising quiet and focus, throughout the church, which results from having no papers, programs, and books to mess with, pick up, put down, leaf through, etc. It produces much more of a sense of community.
Again, it’s kind of a moot point for the vast majority of existing churches where such an arrangement will not be possible or smooth or non-distracting. I’m sure it’s possible to reconstruct portions of some interiors to allow for this (with additional mid-way screens for longer naves), but undoubtedly that would entail some controversy, with someone’s favorite statue, icon, etc. being removed.