What you need:
1 USB Gamepad (I used an old Gravis Gamepad Pro.)
1 small project box
10 push-button n.o. switches (Normally Open: Contact closes when button pressed.)
10 LEDs & 220-Ohm resistors (optional)
These parts should run you about $10, less if you scavenge LED and switches from old electronics. Substitute a small kid's lunch box for the project box and be old school!
Step 1: Tools
drill (I needed 1/4in and 5mm bits)
ruler and square
solder, solder braid (clean up messes)
rubber feet (so it doesn't move as you're jamming)
small spool of shielded wire
Step 2: Obtain a USB Gamepad
Step 3: Remove the Screws From the Back of the Gamepad
Step 4: Carefully Unscrew the Controller Board
Step 5: Gently Pry Controller Board From Gamepad
I tossed the plastic gamepad in the recycler since Gravis was kind enough to have their plastic stamped for recycling.
Step 6: Solder Wires to Each of the Two Contacts (see Next Step)
Or solder using a ground. (see next step)
Step 7: Solder Wire Contacts With Ground (optional)
Step 8: Label and Secure the Control Board
Step 9: Solder Resistor to the LEDs (optional)
Step 10: Make a Template
Step 11: Measure and Drill
Step 12: Solder LED to Switch (optional)
Step 13: Secure the Control Board to the Project Box
Step 14: Solder the Pad to the Switch
Step 15: Drill Hole for Strain Relief
Step 16: Install Software
Joystick to Midi program ( MJoy, Joy2Midi, Rejoice, GlovePIE )
Virtual midi cable program ( MIDI Yoke or Maple Cable)
Mac users can use MultiControl or ControllerMate
Linux users, I don't know what application you need. I know they do exist however.
You will need to reboot after you install a virtual midi cable program.
If you have a joystick with more than x,y axis MJoy is the superior app. However it's limited to only six buttons. If your joystick has many buttons, Rejoice or Joy2Midi is better. GlovePIE requires some coding.
Set the Midi Out of joystick app to Midi Yoke 1. Then in your audio app, set Midi In to Midi Yoke 1.
Here is a video of someone using Midi Yoke and Rejoice:
*note: The link in the video for Rejoice is broken.
Step 17: Make Great Music
All the makers of the free software, thanks for your hard work