FAQ: How do I mark which bands I saw and didn't see at a concert?
To select the bands you saw, click the button that says "Select the bands you saw" at the top of the Band Line-Up section.

When you click that, you'll see check marks appear next to each of the bands in the Line-up. Uncheck the box for each of the bands you didn't see.

When you are finished, click the 'Done' button.