I guess I'm wanting people to realize that they already have a library of building blocks in their own imaginations. "writing music" is a vast thing to say. Writing music in the manner of Mozart or LMFAO or Bruno Mars is narrower. But you have to study those exact folks to do that and then immitate their vocabulary of chords, rhythms, forms, orchestrations, styles... even to say "writing jazz in real time" isn't narrow enough. Jazz is too vast. I think people limit themselves when they get vast unknowingly like this. Better to improvise as one's self than to immitate someone else. If you want someone else to play it back as you wrote it... record yourself.