Follow the instructions below to setup the Guitar instrument in GarageBand to be controlled by the Motion Synth App (Preset 4).
To make it easier to follow these instructions while also using your iPhone or iPod touch, you can email a link to these instructions to yourself on another computer here:
Email setup instructions
TIP: The sound produced by GarageBand will sound much better over headphones, or connected to a good quality amplifier via an audio cable. Don't play the audio wirelessly (e.g. via a bluetooth speaker) as this will produce a disconcerting amount of latency.
In the description below the Single-Key version of the App is used to demonstrate the setup.
If you using the Multi-Key version, you can still use these instructions to get setup with Garageband.
In Multi-Key mode you will be able to choose the notes you play via the 8 key grid, rather than playing through a set melody via a single key.
TIP: If you are using the Multi-Key version of the App you can still activate Single-Key mode.
Learn how best to hold your iPhone or iPod touch while playing here: How to hold your iPhone or iPod touch (without an MS grip)