I started wondering around and found something similar to arduino called - Teensy. It has usb implemented in itself, even better - through ide it is possible to set the type of the device. In our case the device should be... super simple midi device. As I knew something about synthesizers (actually I dont but he thought so) and I was encouraging him to try to find a way make that arduino speak "in MIDI", knowing that such thing will allow connect it with any sampler or specifically build synthesizer for it.
As I was tinkering before with Outsim Synthmaker, I offered to build a software demo version of such a sampler (download here exe and dll version). I never worked with samples in Synthmaker before, so this task was kind a challenge for me. After he defined what he wanted, I made little 6 sample midi sampler starting with C3 key. It has implemented release - so it will sound 30% after after releasing a key.
It can load samples and it shows loaded samples in GUI. It has 3 classes of loudness which are adjustable with two knobs for each sample. Each sample is testable directly in GUI and for each there is main volume and pan option.