There was an news story a little over a month ago about a certain app called SimplePiano (link to the story), which was, as its name states, a simple piano application with limited functionality. Unfortunately, the dev had to drop the project, but it was quickly picked up by XDA member zevele, who has been working on it. The dev just released his improved version 4.2, which among several fixes, it has dual-touch enabled. The app works with most versions of WM and it is designed for VGA and WVGA resolutions.
As the name suggests it’s a simple piano application. I took over “CrisRowlands SimplePiano” after Cris decided to give up developing it (Original thread: forum.xda-developers.com/showthread.php?t=669228). The main reason I took over is because I wanted to implement multitouch. I own HTC HD2 so my emphasize was on the WVGA format, but the application should also support VGA resolution. It should be pretty easy to create skins for other resolutions as well…
You can find more information in the application thread._________