Tutorial: I'm not going to do any tutorial on this.
Mañana de primavera en Marte
The coolest thing here is, I think, percussion. I don't remember exactly how I did that expansive effect, but I guess that I've changed tempo and pitch with Rezound. This track is an improvisation (take #2), hence you can listen a couple of notes out of key to the end. It was the first one that I've played with the computer keyboard. It has that freshness and should remain like that.
The track is in ogg format. If you cannot play it, you should download a browser like Firefox or Chrome.
PlayOgg!