The organisation of the note sequences that form Belcanto words is not driven by a logical structure connected with the notes themselves but purely by the ergonomics. Often used words are both shorter and also are played in a 'hand rocking' fashion, so that one should not need to double tap a single note (which is always slower and harder). Commonly used word combination's should also be nice to play in a fluid way as a sequence.
Last year we spent quite a bit of time tuning the lexicon along these lines, and it did seem more important to get the ergonomics right at the expense of making the vocabulary follow a logical schema. This is of course a trade off between ease of learning and eventual ease of use, but since Belcanto is regarded as a 'power player' kind of facility, we made the tradeoff for eventual playability.
It's actually not that hard to learn the whole lexicon - Sam and Dave did it in around two weeks. They just learned it, away from the instrument, in the same way one learns vocab when learning a foreign language. I actually set an exam (I am a horrible man), giving them a week to get it right (along with all the million other things they had to do last summer) and they both got 100% over 50 questions, which impressed me no end. So it's certainly possible, even not that difficult, to learn the vocbulary. Physical ease with playing it, coupled with knowing what the words do and how to use them, is just a matter of practice, just like every other thing in music. A few minutes a day spread over a couple of months and you will get good at it. It's just the small matter (!) of finding that couple of minutes, and persisting through all the inevitable frustrations that you will bump into in that time.
Just as a note, all words starting with '8' are temporary assignments - we usually add vocabulary and see how its used before putting a word in it's permanent home - so please don't get upset when I move them from there later.
If there is sufficient interest, we can arrange some Skype tutorial sessions with Dave for a group of Belcanto learners, please post here if you are interested. I am genuinely excited by the prospect that some of our players are now moving on to have a go with this feature and we'll help you if we can, along with welcoming comments on it's improvement from people learning.
John