This is a case I made for my DIY imaginary trombone from the imaginary marching band blog. The imaginary trombone is a cool thing that has a pressure sensor and a distance sensor to play an arduino using serial to MIDI just like a trombone.first you need to test your pressure sensor and ping with the codes listed below. then upload the code onto an arduino using the schematic from http://imaginarymarchingband.com/blog/diy/trombone. then you will need to download the Serial to MIDI converter (refer to same site for more details). Go to: http://imaginarymarchingband.com/blog/diy/trombone for more information on the schematic and insructions for Serial to MIDI