For the full fun experience of this WebMidi experiment you'll need a minim MIDI controller.
If you have a minim controller then we need to get it connected to your Mac and you'll need a recent version of Google Chrome.
There are two very handy tools that come with your Mac that we'll need. If you open 'Audio MIDI Setup' and goto the Window menu and select 'Show MIDI Studio' then click on the Bluetooth logo.
At this point you need to make sure your minim is switched on, then it'll appear in a list in the new window. All you need to do is press the 'Connect' button.
To test that minim is able to communicate successfully with your computer open up 'MIDI Monitor' and make sure that MIDI Sources is checked, which is within the Sources expander.
Hopefully your minim is still connected and if you start hitting the pads you will see messages coming through in the MIDI monitor.
With all that in place your minim is very much connected. Now refresh this page to allow the browser to connect to the minim and let's see what happens.
Code for this demo can be found at github.com/jiggypete/minim and you can find me, @jiggy_pete, on the Twitters!