MacOS – How to play a MIDI file on the MIDI keyboard

QuickTime Player 7 also supports mid files.

Many DAWs like Logic support importing and exporting mid files, but one free MIDI sequencer or editor is Aria Maestosa. Synthesia is an application or rhythm game for practicing playing mid files.

This turned out to be a more complicated problem than I originally expected.

QuickTime X cannot play MIDI files, although QuickTime 7 could.

As far as I can tell that means that there is no "built-in" solution to playing MIDI files on Mac OS X (for example, afplay does not work). Therefore I believe that any solution will involve downloading and installing some other program.

Option #1: Download and install QuickTime 7 which still works fine on Mavericks, and then you can play midi files by:

open -a QuickTime\ Player\ 7 /path/to/your/file.mid 

however that will only autoplay if the user has enabled that preference, which I believe is off by default.

Option #2: Use FluidSynth

To install it, you have to be using either Fink, MacPorts, or (my recommendation) Homebrew. Once Homebrew is installed, type this in Terminal:

brew install fluidsynth

(MacPorts' command would be sudo port install fluidsynth and Fink's would be fink install fluidsynth.)

However, downloading fluidsynth only gets you part-way there. Then you need a "SoundFont" file, which I had never heard of before. There is information about them here

I downloaded one from S. Christian Collins called "GeneralUser" which is free. The current version (as of 2013-11-27) is FluidSynth version 1.44. {If that direct link breaks in the future, use the previous link which will take you to the regular web page for GeneralUser.}

Once you have downloaded and unzipped that, you will have a series of files including "GeneralUser GS FluidSynth v1.44.sf2" (obviously the name may change in the future). I renamed that file and moved it to /usr/local/share/fluidsynth/generaluser.v.1.44.sf2.

Once the SoundFont file is place and fluidsynth is installed, you can play a midi by using this command:

fluidsynth -i /usr/local/share/fluidsynth/generaluser.v.1.44.sf2 ~/Music/example.mid 

n.b. There are some (seemingly harmless) error messages which get displayed when you do that. If you want to suppress them use:

(fluidsynth -i /usr/local/share/fluidsynth/generaluser.v.1.44.sf2 ~/Music/example.mid 2>&1) >/dev/null

instead.

Obviously I'm never going to remember all of that, so I made a zsh function called playmidi

function playmidi {

    SOUNDFONT='/usr/local/share/fluidsynth/generaluser.v.1.44.sf2'

    if [ -e "$SOUNDFONT" ]
    then 

        for i in "$@"
        do 
            if [ -e "$i" ]
            then
                (fluidsynth -i "$SOUNDFONT" "$i"  2>&1) >/dev/null
            else
                echo "[playmidi]: cannot find file at $i"   
                return 1
            fi  
        done 
    else
            echo "[playmidi]: SOUNDFONT file not found at $SOUNDFONT"
            return 1
    fi  
}

(That should work for bash too I believe.)

Now all I have to do is type:

playmidi example.mid 

and example.mid will play.