This is a game made during the C3 hackathon at UofT. This uses the Slick2D engine as graphics and audio support and everything else was made within 24 hours.
This game takes audio input from the microphone, analyse the pitch, and tries to map it to a MIDI file. Think of it as a guitar-hero like game except for real instruments.
Please note that this is just a prove of concept and is in no way polished.
If you would like to have a example on using audio data with your Slick2D game, feel free to take this code and use it anywhere you want. :)