Agent A: A puzzle in disguise

Missable

You can do this in Chapter 1 or Chapter 2. When you're inside Ruby's house (in the lobby with the fish tank), go inside the room directly in front of you (the one with the fireplace). Interact with the stairs to go up to the Library/Piano Room. Once inside, interact with the piano until you are fully zoomed in on it. On the left, you'll notice there's a key with a marking on it:

Hold down this key with and (while still holding ) move your cursor quickly along all the keys to the right to perform a glissando glide. Once you have, the trophy will unlock.