The pictures adjacent show the application I am interested in, and that is providing guide lights for a piano, organ or digital piano.
These two test programs are only a beginning and the prototype is little more than proof of concept at present.
The traditional approach is to use a MIDI decoder, and there are several products (circuit boards) available that decode MIDI messages and enable 64 outputs. But MIDI is really overkill for just switching on LEDs. Also, there is a need to be able to switch on an LED a fraction of a second ahead of the actual note sounding. If an LED lighted at exactly the same time as the MIDI “note on” message being received (and thus played by the instrument), then it would be rather like an orchestral conductor waving the baton exactly synchronous with the music being performed (conductors are always slightly ahead of the performance).
It is far easier to conceive of a simple on/off command set using an RS-232 connection to a Basic Stamp or similar microcontroller than converting a MIDI file in such a way as to light the LEDs momentarily earlier.
The next step will be to work out a way to light more than 8 LEDs and I shall probably use cheap and cheerful CMOS or TTL latches for this. These pages will be updated as and when I have a further prototype available.
I have included the source code for these test programs in a ZIP file.