This trophy is story related and unmissable.
You will get this trophy after breaking Doc out of the Citizen Plus building. After Jennifer frees you from your cell, you next goal is to help Doc. Start by taking control of the control panel (Use Biff's pill to knock out the guard on duty), and turning up the volume. Next, turn up the olfactory senses, which will cause Edna and the other guard to go down and try to fix it. Enter the room that they were just in and equip your guitar. Interact with the microphone and your trophy will unlock as soon as this scene ends
Refer to the Trophy Walkthrough under "To The Expo!" , for more.