This idea's time has so thoroughly come that I am probably too late to claim credit for it, but hey - if even a small part of it hasn't been tried out, remember whom to tip when you sell the idea for a zillion bucks.
What if all this was replaced by large, touch-screen Android tablets or iPads dedicated to a scoring app that displays each performer's part? Let's call this app, for the sake of example, ScoreFish (*blush*). Here are some of my ideas about how ScoreFish could work.
First, each musician (including chorus members and soloists) would be able to log into any tablet on, say, the orchestra's network. Once logged in, he (or she) could open a full orchestral score of all the pieces being prepared and performed for the time being, or just the ones a given performer is involved in, at the discretion of the music librarian. This can be drilled down to a view of the performer's part only, or his section of the orchestra, or (for singers) a vocal score with piano reduction and the individual user's part picked out in bold type, etc.
Annotations could be added and deleted by hand using a touch-screen stylus, either by the musician or by a conductor preparing scores for his musicians. Maybe with handwriting-recognition software the annotations could be added to the score as though part of the printed music (not sure whether this is a great idea, though). Each musician's, singer's or conductor's annotations could be saved as a customized version of the score in case they are ever called for again, a few seasons down the road; the original score is unalterable and can always be reverted to if necessary.
Page turns during performance or rehearsal could be triggered either by tapping a spot on the screen or, with a webcam, making a certain gesture like a jerk of the head or a flick of the wrist - even, heaven knows, a page-turning gesture of the hand. Or there might even be some way to program the pages to turn themselves in sync with the performance, either using a microphone and sound recognition software or (during a performance) some type of remote controller that keeps all the tablets on the same page of music, like how someone in the sound booth keeps the supertitles on the screen above the stage in sync with the singers. Who knows if it couldn't be programmed to follow the conductor's gesture!
Chorus scores could include IPA symbols for the lyrics, a translation of the text on every page, and a choice of languages to sing the work in, any of which can be completely or partly shown or hidden at the user's discretion, and annotated as well. "Road-mapping" marks, such as when a few singers in the Tenor 1 section are asked to dart up to the Alto 2 line for a few notes, or when some but not all members of a section are asked to sing a particular passage, or when different chords are divided up in different ways, could be reflected in each individual chorus member's part.
A playback function could be included for rehearsal purposes, complete with an optional metronome tick that can be raised or lowered in volume or muted altogether, adjustable speed (for rehearsing slowly, then working up toward a target tempo), and the ability to select whether to play the full orchestra, a custom-selected group of instruments or voice parts, or a piano reduction. Also up to choice is whether to mute one's own part, play it at the appropriate dynamic level, or shine an audio spotlight on it by playing it louder or doubling it with another instrument.
Playback could, of course, take place over on-board speakers, external speakers or headphones. The tuning could be adjusted to the frequency chosen by the orchestra (which can vary depending on which century's practice it is based on). A conductor-sensitive playback, perhaps using a special device that scans the conductor's movements and syncs with other devices on the stage, could even be used, if necessary, to replace absent members of an orchestra with a virtual performer. I can even imagine it being used to replace an entire pit orchestra for, say, a small school musical.
The tablets would have to be mounted in such a way that they would stay put. Traditional music stands may or may not do the trick. Also, power supply would be an issue - it would have to get every member of the orchestra through a performance potentially three or four hours long, if not longer. There might not be a battery in the world that could do this. But maybe a custom stand could be included with a built-in charging port or an immediate source of power to run the device, provided this could be plugged into a power outlet somewhere under the stage. To be able to move these stands around while the stage is being reset during an intermission could be a difficulty, requiring a new concept of stage design. Or maybe someone will finally surprise us all by announcing the discovery of broadcast power, sending energy via a wireless link.
If a tablet is stolen or lost, it can simply be deleted from the library's account and remotely deactivated. As the concert season progresses, pieces whose performance dates have passed can be removed as new pieces to be rehearsed are added, again at the music librarian's discretion or as requested by a user. If they can take their devices home with them to woodshed their part, it stands to reason they may also add any score they desire to their account, provided a licensing fee has been paid either by the user (who has a unique sign-in ID for the app to access files on the cloud) or by the score library. And so even copyright law is covered.
Also, someone could keep track of statistics of how much time each member of the ensemble spends woodshedding his or her part. Maybe there could be a bonus for the most effort.
How does that sound, music nerds?
Crap. Now that I Google it, I see a lot of it has already been done. (The image above is an app called Scorch.) Cool, though.