In the Finder, make a folder of sounds to use to build your instrument. These can be anything you like, as long as they’re audio files in .wav, .aif or .mp3 format.
Click the ‘New Project’ sidebar and choose ‘Piano’. In the next screen, give your project a name, choose where to save it on your hard drive and click ‘Create’.
Over to the right-hand side of the screen, in the Track Info pane, select Sound Effects>Radio Sounds from the instrument list.
Select Musical Typing from the Window menu, or use the Shift+Cmd+K keyboard shortcut to reveal the Musical Typing window.
The most popular starting note for sample-based instruments is C1, so click the upper keyboard display or press the Z key until the Octave display reads C1.
From the Finder window containing your drum samples, drag and drop them one by one onto the required keys. This initial window contains 18 key slots.
If you fill up the first 18 key slots, access the next 12 empty ones by tapping the X key to shift the keyboard range up one octave.
After placing your samples, pick a category to save your instrument in from the list and click the Save Instrument button. Type a name for your instrument and click Save.
Your new instrument’s name should now appear in the list. Like regular instruments, it will now be accessible for all your future GarageBand projects.
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