Recently I have got an idea to blend the old MMO recordings with digital sheet music (something like xml, sib files) that will guide the pianist along the notes. As we can see if we play along the accompaniment tracks, we will encounter several problems:
1. Difficult to follow through the music at exact beats (When the solo comes in, orchestra will sound softer making it even harder)
2. To practise by adjusting the tempo manually within specific passages (reduced tempo version available but it is too annoying to switch between tracks and to be at exact bars)
3. Some old recordings contain annoying tappings, which is not appropriate if you play in front of audience (can be removed manually by audacity, new recordings don't have taps)
4. Hard to catch up with orchestra after long solo passages, which easily demotivates the player (they will focus on adjusting their rhythm instead of technique)
5. To start at specific bars or even notes (one way is to split the music into multiple tracks but not granular enough)
6. Page scrolling causes missing of tempo (very old problem which can be solved easily in digital age)
I have found a way to address the problems above but I need a clean and correct digital score in xml format, maybe some scanning recognition software will help.
Another software that blends the recording (with piano) with the score, create sync-points while music is playing, then transfer the sync-points to another recording without the piano and make some fine adjustments.
Currently working on Beethoven Piano Concerto No. 1 (all movements), Largo is done and I will publish a youtube excerpt of it.