Playing Mac Pro Audio - Teach Yourself Visually Complete Mac Pro - page 504

Select all the songs that you want to edit.
Note: To select individual songs, press and hold and click each song; to select all
songs (on a music CD, for example), press + .
Click File .
Click Get Info .
Note: You can also press + . Alternatively, right-click any selected song and then
click Get Info .
iTunes asks you to confirm that you want to edit multiple songs.
Click Yes .
The Multiple Item Information dialog appears.