Convert MIDI to MP3 with Garage Band

With many schools not in session due to COVID-19, vocal music teachers may be interested in learning how to convert midi files into MP3’s so that their students can continue to learn their choir music quickly and accurately.
The method outlined below is using Garage Band with OSX, El Capitan, v10.11.6.

Navigate to the midi file to be converted.
Right click (Control click) on the file name.

Select ‘Open With’ Garage Band.

Importing the file in this way ensures that tempo and time signature information is brought in correctly.

Edit the playback instrument for each track.
Octavo Midi does not embed instrument ‘patch’ information, so Garage Band is choosing these patches initially. You can then choose whatever works best for you.

Press ‘Y’ on the computer keyboard to open the Instrument Library.

Select a track, and then navigate to the instrument desired.

You may need to click on ‘Orchestral’ or ‘Synthesizer’ at the very bottom of the Instrument Library window to see all of the instrument ‘folders’.

Fix the playback octave of one of the tracks.
For whatever reason, one of the tracks may have ‘(12 Semitones)’ at the beginning of the track and will sound an octave higher than intended.
To fix this:

Double click within the track itself. This will bring up the ‘Piano Roll’ window at the bottom of the screen. 

Click the ‘Region’ tab in the left-hand portion of the Piano Roll window.

If needed, grab the window top border and drag up, enlarging the window, until ‘Transpose’ appears at the bottom left of the window.

Drag the transpose slider to the left until you reach 0.

Double click within the track itself again to get rid of the Piano Roll window.

Solo the tracks you want to record
Click the Headphone icon in each track header.

 

Adjust the Pan and Volume of each track.
I always pan the Piano (accompaniment) track to the Left channel and the voice part I’m recording to the Right channel. In this way, the student can easily discern his/her part even if the instrumentation is the same on both. I usually also lower the volume of the accompaniment track just a bit. 

 

Convert to MP3
Click ‘Share’ in the main menu, and then select ‘Export Song to Disk’.

 

Complete the process.

Give the MP3 a name to identify the song and voice part.

Navigate to where you want the file to be saved.

Select MP3 from the options at the bottom. 

Click OK.

 

Locate the MP3, click to select, and then press the spacebar to hear the result. Now you can easily email or otherwise share the file with your students.

Navigate to the midi file to be converted.

Edit the playback instruments.

Fix the playback octave.

Solo tracks to record

Adjust Pan and Volume