It is possible to place music notes on a track in garageband. If you click on the notes you can select them. They will turn from black to green. It is possible to add notes by clicking on the note icon and apple clicking on the line and the note will be added.
1 below opens the view required. 2 displays the notes. 3 displays the staff. 4 Allows you to change the type of note.
Rogue Amoeba is providing some very useful software if you need to be able to quickly change the audio input or output of your computer. Changing audio quickly on the fly is very helpful if you are podcasting or working with MIDI devices.
The software is not approved at this time, so you can't install it on your teacher laptop or other school computers, but I will submit it for approval. Check the software approval list or watch this blog for announcements.