Ensure that “Play sounds from your Mac” is selected and click the “Create” button:
Close the “Musical Typing” window:
Select “Show Smart Controls” from the “View” menu:
Click on the “i” button to show the inspector:
The inspector is now displayed but only shows the keyboard sensitivity (major design flaw in Garageband):
Drag the horizontal border that is immediately above the inspector upwards and the Audio Units panel will come into view:
Select AU Instruments->Humanoid Sound Systems->Enzyme->Stereo as shown below:
Enzyme Player is now loaded:
If you have a MIDI keyboard then plug it into your computer to play Enzyme (or Enzyme Player). If you do not have a MIDI keyboard then you can use the “Musical Typing” feature of Garageband. As shown below. A MIDI keyboard is strongly recommended however, as this allows a lot more expression than the computer keyboard and is how most people will choose to play a synthesiser.
The “Musical Typing” keyboard, which can either be played by clicking its keys or using the corresponding keys on the computer keyboard and changing the octave using the Z and X keys:
Different factory preset sounds can be selected by clicking on the preset name (which will initially be “ATMOS BassStorm") to bring up the preset menu, and selecting a new preset. Each preset produces a different sound from the synth.