Jake: I would like to concentrate on some of my favourite authors (Bach, Beethoven, Chopin and Schubert)
Jake,
You will find much in the works of Franz Schubert that can be transcribed for theremin but the same cannot be said for Bach, Beethoven or Chopin.
The theremin is an extremely limited instrument. The few things that it can do in the hands of a skilled player it does magnificently but when pushed too far the inherent flaws in the space control concept become obvious even to the most unsophisticated listener.
The music of Bach, and most of the music of the baroque period, requires the ability to play connected notes, and staccato notes, accurately over large intervals (two things that are impossible to do consistently and precisely on a theremin). There are a few melodies that are possible (such as the so-called "AIR ON THE G STRING") but most of Bach's work is best avoided by thereminists.
Beethoven, as undeniably brilliant as he was, is widely regarded by musicologists as a poor melodist. Schubert, by contrast, is considered one of the finest melodists who ever lived. The theremin plays MELODY and there is little in the Beethoven repertoire that suits it. Samuel Hoffman recorded the MOONLIGHT SONATA but it doesn't really work because the melody, like so many other melodies of Beethoven, is a sort of "Johnny one-note" affair that depends entirely for its effect on the mood created by the shifting harmonies that are going on behind it.
Chopin's work was created for the piano and regardless of how one feels about it, it contains some of the cleverest and most beautifully crafted keyboard masterpieces ever composed. You cannot even have a conversation about the development of the modern keyboard without some discussion of the astonishing contribution of Frederic Chopin.
When you begin to transcribe Chopin's music for other instruments, you realize very quickly just how keyboard-dependent his compositions are for their extraordinary impact. Even the celebrated orchestral transcription LES SYLPHIDES, by none other than Alexander Glazunov himself, lacks the inimitable charm of the original piano pieces it is based on.
Clara Rockmore recorded the C# Minor Nocturne and runs into trouble in the first bar where there is an extended, highly "chopinesque", half note trill that ends up sounding vaguely like IT CAME FROM OUTER SPACE when played on the theremin.
Schubert is an untapped gold mine for the theremin.
Back in the late 90's (before the Levnet, when we communicated via alt.music.makers) someone wanted to purchase a theremin strictly for playing the Bach unaccompanied cello suites. In her musical imagination, this person could clearly hear the suites being played on the instrument and she was convinced she could learn to do it. I suggested that if that was all she wanted to play, she should learn the cello instead because it is far easier than the theremin and the suites cannot be played on the theremin anyway no matter how skilled you are.
Prior to any real, practical experience with the theremin, people often overestimate what is possible and are absolutely convinced that if they only had an instrument they could do all sorts of things that are simply not possible.
If these people are genuinely musical, once they start to play they quickly realize how misguided they were. If they are not musical, they join the ranks of the "Joe Theremins" of this world, who are great theremin virtuosos in the concert halls of their own imaginations.