Hey! I don't really have the required experience to talk about it in toki pona, so sorry for using english (though I speak esperanto but don't know if most of people do, here).
I have nearly finished the creation of a musical language (sort of toki pona-solrésol) called La La (the name might change), which is based on the pentatonic range, but can be adapted to all other ranges, I'll explain it another post because I have still to fix something.
It has no real point other than to create a new type of poetry, I let you imagine what you could do with it.
When I say it is musical toki pona, I only mean that the vocab of concepts is practically the same. But of course it sounds differently (more like someone singing La-a-a-ay Lay-lay on a pentatonic range).
The problem is that, indeed it is based on toki pona vocab, thence I need some global statistics for frequency of word use (dont' know if it is correct english, -esperantlingve estas vortuzfrekvenco), as most used words have to use the shortest and easiest melodies and the less used get the long and more difficult one (even if it is never more than three notes).
I would be pleased to have a link about any large statistic about toki pona word frequency. When my language will be done, I will probably post it here.
I know that there is a big corpus on tokipona.net, and I was ready to collect statistics directly from it (though it is a long task) but I thought that maybe there was already some done. So if you could help in any way, thank you from advance!
Ps: Actually nobody knows who the hell I am, newcomer not even presenting himself, I hope it doesn't irritate you. Since it is not the proper section to talk about me, I'll present myself another time