I’ll say what I always say: make it a hypercoaster and call it Hollywood Rip Ride Remix.
Make the “secret song” keypad the primary infrastructure for song selection and partner up with a streaming service to sponsor the ride and handle music licensing. Say Spotify offers up a “slice” of their app through the UO app, 100 songs from 10 genres (or 100 genres from 9 and 99 from 1, for 999, so you can keep a 3-digit format) that get updated regularly. You pick a song in the app, get your number out of 999, punch it in once you get on, off you go.