Apple's DLSMusicDevice — the good news and the bad

So what does the DLSMusicDevice do?

If you've ever clicked on the Generators popup menu on the Track Info window, you may have been intrigued by this Apple-made audio unit — and you'll only be more so when you learn that DLS stands for downloadable sounds. The DLSMusicDevice is designed to play downloadable sounds in the SoundFont format, many of which are freely available on the internet. It also lets you play the QuickTime musical instruments that come with your Mac...

...Um, sort of. Because, for GarageBand users, the DLSMusicDevice isn't all good news.

What DLSMusicDevice does do in GarageBand

If you download a SoundFont (a file with a .SF2 file extension; you may have to use sfArkXTc to decompress it — it's freely available) from the internet and put it in your ~/Library/Audio/Sounds/Banks/ folder (you may have to create the folder first), when you create a track that uses the DLSMusicDevice as its generator and click the edit button, you will see a list of all available SoundFonts in this location on your system:

Select one, play a few notes and you'll hear it coming through, as expected. All well and good.

What DLSMusicDevice doesn't do in GarageBand

But what if you select QuickTime music synthesiser? You get the piano sound. But what if you want to select one of the other QuickTime instruments, of which there are quite a few? Or, what if you have downloaded a SoundFont with several sound banks in it — how do you choose a different bank?

The answer is that, if you have a MIDI keyboard, you send a program change MIDI event. The trouble is that although this will change the sound bank you hear when you play, GarageBand doesn't save this information. When you next open the song in GarageBand, DLSMusicDevice will have gone back to the default sound bank for the chosen SoundFont.

And, of course, if you don't have a MIDI keyboard, you can't even do that.

It's a pity Apple did add just one more setting to their DLSMusicDevice to allow you to change the sound bank. However, there is a solution in the shape of the shareware program SoundFont Synth, reviewed on this site here.