My solution requires an iPad:
I’m lucky enough to have musician friends and so I could partner up with one of them. To show him what I had in mind in sort of tone and feel to the music I decided to make a temp track, facing with the same problems I remembered that I own an iPad and Apple has published this amazing(!) piece of Software called "Garage band" where you can smartedit your own songs. I have to confess that I do know something about music, but it’s not really much.
tl/dr: If you do have an iPad give GarageBand a try.