Ode to Joy can only be obtained by 4 players each playing with a controller (no keyboard player is allowed) doing a happy emote (Y button on the Xbox controller) at the same time. "At the same time" seems to be very loose, the timing is very easy to hit. You can do this on any level.
If you do it and don't get the trophy, either you did the wrong emote (pick characters without a costume to see their faces, it will allow you to make sure you do the right emote) or one of your players is playing on the keyboard.