Train your ears, everyday.
Most music is in a particular key. The key is the tonal home of the song. If we say that a song is 'in the key of C', this means that the pitch C sounds like the most stable “home note” (or tonic) for the song.
Learning how to determine what key a song or piece of music is in is a valuable musical skill. This game is going to challenge you to guess the key of a random song. Listen to it by ear first, try to guess. Then, if that didn't get you closer, use your instrument for a relative pitch.