By default a new Logic project's Key signature is set to "C". Of course not all your compositions need to remain in the Key of C! You can adjust this for your entire project and create key changes at different points in your project. This is perfect when creating a Score in Logic.
These key signature changes throughout your project will only affect the display of MIDI notes in the Score Editor. They won't, however, have any impact or make any changes to the playback of the MIDI notes.
If you want to affect the playback key of the MIDI notes you can use the following techniques substituting the Transposition global track for the Signature global track.
Read on to discover more...
Click on the disclosure triangle next to the word Global Tracks above the Track List. You can also use the default key command (mine is "G").
You should see a selected array of Global Tracks available. However, like normal tracks they can be expanded or resized. Either click on the disclosure triangle next to the Signature track:
or position your mouse cursor over the horizontal boundary lines between the global track. You'll notice your mouse cursor turns into a resize tool.
Drag to resize the Global Track:
To create a key change, right-click anywhere in the Key lane to see this menu:
Choose "Create Key change" and you should see the Key Signature dialog window appear:
NOTE: Alternatively, use the Pencil tool and click in the Key lane where you want to make a change to the project's signature.
Once you've selected the key, click OK. And here we have the Key change in the project:
NOTE: You can customise the Global Tracks to view by right-clicking (control-clicking) on any Global Track to see this menu, where you can choose which ones to view and which ones to hide:
Want to learn more about Global Tracks and Logic? Check out the Logic 101!