i made this using 'V2 Synthesizer System' by farbrausch, it's a special softsynth VSTi that incorporates MIDI features, so you can feed MIDI notes, control parameters, assign channels and record a tiny .v2m file (2~200kb in size). it was designed as a means to include high quality music in a small filesize, in demoscene productions-- all sound is rendered in real time from notes/settings recorded into the v2m file, this song i wrote in particular is only 17,268 bytes (16kb)

I used FL Studio to write the notes so i still had the same familiar interface that i'm used to, and i could use quite a bit FL Studio features (eg. arpeggio) and it all reflected nicely-- seems the possibilities are endless with this, but sadly not much v2m music is any good