A while ago I bought an M-Audio Keystation 61es because of it's low price and quite good features and quality. Most people who've bought this keyboard use it like a midi keyboard (which of course it is), but I bought it to learn how to play piano. Although I'm really happy with this keyboard, it doesn't have any integrated speakers so you'll always need to connect it to some kind of computer to generate any audio. M-Audio does give you a version of Ableton Live Lite to hear the tunes you play but this is quite devious if you just want to play some piano.

After some research I found a nice little program called FluidSynth. FluidSynth is capable of  converting those digital midi signals to nice instrumental sounds. What is also nice about FluidSynth is that it runs just as easy on Linux. And that's what caught my attention because I got the idea to create a cheap Raspberry Pi synthesizer for this keyboard which I would just need to connect to some speakers et voila, piano music.

To get FluidSynth to work on Windows follow these instructions.

1. Download FluidSynth Windows binaries, if you need to, choose the zip file.
   
2. Download some compatible sf2 files (these are soundfonts and contain the sampled data with the audio of, for example, a piano). Remark: some sf2 files are not compatible with FluidSynth.
   1. GeneralUser_GS_1.44-FluidSynth at S. Christian Collins' page (worked best for me)
   2. Acoustic piano's at zenvoid
3. Connect your midi keyboard
4. Start FluidSynth (it should automatically detect your keyboard but doesn't give a message about it)
5. Load the soundfont by 'load "C:/Path/To/Font.sf"
6. Strike a key on the keyboard, it should produce a sound now
7. If it doesn't produce a sound, try setting the gain higher by 'gain x' where x is the gain (1, 2, 3, 4 or 5)