Raspberry Pi, Clumsy MIDI and MT32-Pi – Part 2

This is a short follow-up to my previous post – Raspberry Pi, Clumsy MIDI and MT32-Pi – to explore the General MIDI capabilities of the MT32-Pi.

Warning! I strongly recommend using old or second hand equipment for your experiments.  I am not responsible for any damage to expensive instruments!

If you are new to the Raspberry Pi, here are some resources to get you started.

• Getting Started with the Raspberry Pi Article
• Getting Started with the Raspberry Pi Tutorial
• Adafruit Raspberry Pi Lessons

Other links to resources from this project.

• MT32-Pi Project
• Clumsy MIDI Interface

Parts list

• Raspberry Pi model 3 or 4.
• Power supply.
• Micro SD card.
• MT32-Pi supported sound board (optional) – I built myself a Clumsy MIDI interface (see below).
• MIDI source device and appropriate leads.

The Hardware

I’m using my module as built and described in the previous project.  The difference is that this time I have switched over to my authentic Roland UM-ONE MIDI interface.  The cheap “no-name” one from the online auction site just couldn’t cope with a full MIDI file complete with full expression, control and program changes.

Configuration and Use

The MT32-Pi comes with a built-in General MIDI synth in addition to the MT-32 support.  You can get to it in several ways, but in my case I edited the mt32-pi.cfg file to change the default synth.

default_synth = soundfont

You can read all the details here, but this switches the synthesis engine from the Munt MT-32 emulator to the Fluidsynth Sound Font synthesizer.  There are a whole range of “fonts” you can download and install (see here for a recommended list), but by default it comes with the “GeneralUser GS” sound font.

This gives you a full General MIDI compatible set of sounds and configuration.  The producer S. Christian Collins describes it as follows:

GeneralUser GS is a GM and GS compatible SoundFont bank for composing, playing MIDI files, and retro gaming. It features 259 instrument presets and 11 drum kits, all while possessing a very low memory footprint (less than 30 MB of RAM). Due to its clever, detailed sound programming, GeneralUser GS can sound as good or better than SoundFonts that are 2-3 times its size.

I decided on the name “GeneralUser” because the bank was designed to sound well with all kinds of music rather than specializing in only a few styles, thereby benefiting the general user. It’s not a great name, but that’s what I came up with almost 20 years ago, and I haven’t bothered to change it.

I’ve been playing a number of MIDI files downloaded from www.classicalmidi.co.uk, straight “as they come” through the module and the results are pretty good.

In the first video you can hear Scott P. Anderson’s sequenced version of the Infernal Dance of King Kashchei from Stravinsky’s Firebird Suite (from the ballet of the same name).  There is one wobble around 2 minutes in where I’m not quite sure what is going on.  I don’t know if that is an artifact of the MIDI file itself or if the module is just working too hard here.  But in general I think the results are pretty good.

In the second video below you can hear Jun Nishio’s sequenced version of the first few movements of Stravinsky’s Rite of Spring.  To me, this sounds amazing – I am so impressed with this.

Closing Thoughts

For me, in part, having a General MIDI set up detracts from the amazing technology that goes into providing it.  Just replaying classical MIDI files is a funny one – it will never be as good as a proper recording of a full orchestra, and it doesn’t really benefit from the huge potential of electronic sound synthesis either.

However, to get to the point where it is possible has tied together a whole range of technology, much available freely from a pile of different developers, and each of which has its own potential. So as a demonstration of what the MT32-Pi can do “out of the box”, this is pretty impressive – I’ve personally had to do very little to get this far!

There is plenty to experiment with now, either trying some of the other soundfonts, or seeing what tailoring is possible with the default set.  And I’d still let to get some kind of “user interface” onto my module somehow to make it more of a synth module rather than just a “MIDI sound box”.

Kevin