I think there should be an in app trivia function.
The person with the Spotify account should act as host and question master, playing to a group of friends through a speaker, and be prompted by questions from music trivia about bands and artists, to naming their songs after just hearing the intro, and also
By using the tech and resources from the behind the lyrics team, it should be easy enough to generate a load of questions across genres.
the players will then agree a list of genres or question types for Spotify to randomly assemble and then the question master can kick off!
you could introduce difficultly settings quite easily based on the first pilots and how well people responded.