Final answer:
You can transpose selected MIDI notes by dragging them with the two-sided arrow icon while holding the alt key. Transposing changes the pitch of the notes.
Step-by-step explanation:
Selecting MIDI notes and pressing the alt key and dragging the two-sided arrow icon at the end of the MIDI allows you to transpose the selected notes. Transposing means changing the pitch of the notes. For example, if you select a group of MIDI notes and drag them up, you are transposing them to a higher pitch. Conversely, if you drag them down, you are transposing them to a lower pitch. This can be useful when creating music arrangements or improvising melodies.