thanks, it seems to be really a cool project. But my project is more simple than that sequencer i think.
recording a midi message ( 24 first messages from the midi info received, or less ) , then playing it back, note after note, same spacing between each note.
Then controls for each note, by two options : global velocity for all notes , and global note lenght for all notes. And the second option combined : individual controls for each note ( velocity, lenght ) .
Then, while the sequence is being played in the midi out, the machine can receive a key information by the midi in, to transpose the whole sequence to this note height. that's the base. It might start to be messy when several notes would be played at the same time, so the machine would perhaps have troubles to know where to transpose the sequence.
the perfect example that shows what i'm describing is here at 2:17. See how he transposes the sequence.
then , some features to correct the info about which key it is, on each note. and which steps are blank, and at which step the sequence restarts from the begining, or the other option to have the sequence played only once, or twice, etc ..