(There's no video for Virtual Midi Keyboard 1.6.5 yet. Please contribute to MR and add a video now!)
The name of this application made with Max/Msp does exactly what its name suggests :)
v-m-k-1-6-5-f.sit (809.06 KiB / 828.48 KB)
/ compressed w/ Stuffit
At least 5MB of free RAM
Mac OS 8.x - Mac OS 9.2.2
Note: To run V.M.K you will need a Macintosh PPC computer with OMS properly installed.
Emulating this? It should run fine under: SheepShaver