There's a piece of music done entirely with the 2600V on my download page at
www.myths-and-legends.org/andrew/It's the one called `Intervening Shoreline' near the bottom of the page.
It's part of a larger work based on the so-called `Seahenge' Bronze Age site that was discovered near Holme-next-the-Sea in Britain. The version on the download page is faded down before the end, though. The original piece lasts for about eleven minutes.