Finish audio-visual project in Processing 2

Hi there, I'm pretty new to Processing, and wondered if somebody might have a little bit of time to help me finish/move on a fairly simple sketch. For someone more competent than me, I think this should be a simple job, but it does need to be completed in the next 24 hours. The aim of my program is this: A user should be able to scroll on a trackpad/mousewheel, and hear each of a list of audio tracks being cycled through (ie, each plays one after the other for 2 seconds or so). When/if the user stops scrolling on the trackpad, this is treated as the user "choosing the last played audio track" - the "chosen" track plays through, and a message appears on screen relating to this track. When the user continues to scroll on the trackpad, the list of audio tracks continues to cycle through from the position of the last "chosen" track, and this process repeats like this with the user constantly able to continue scrolling or choose to hear a whole track, until all audio tracks are cycled through. The programme could then loop. That's basically it! I hope you understand what I mean. So far, I've managed to get the mouse wheel playing and stopping tracks and returning "on"/"off" messages every few seconds, but obviously there's quite a way to go. I don't really understand how to deal with events or time more than I already have, and would very much appreciate somebody helping me get this finished. Feel free to send me a message if you've got any questions! Have attached a document outlining the program's aims. Can also send out the code I've got so far if that's useful to see.