this robotic glockenspiel is simply amazing. I believe you've already received useful tips on how to get things transposed, very cool. Nevertheless things may vary from song to song, perhaps most of the "musical choices" one should do in order to achieve a pleasant rendition might be transformed into automation and programmed, i am a musician so i can't advice you on that.
A human being could take into account many aspects at the same time: change the scale if needed, ignore some voices in a poliphonic song etc....
I can do the transcriptions, if you wish. Could we please talk by private message?
Regardless to your will to contact me, i wish to expand on the importance of adapting the scale, this might be useful anyway... let's say your song is in A minor and you feel the bass line playing a F, then G, then A....your glock's lower note is C and you will perform the bass melody too close to the second octave.... transposing everything to E minor could do the job.