My children get exposed to allot of music through my own playing, concerts we take them to and what is available to them via recordings.
There is a strong tendency to parade around the house singing what has recently been heard. We are currently being serenaded by songs from The Beatles, ABBA, Tchaikovsky, Mozart and Beethoven.
Recently they have discovered a case of old cassettes. I predict an explosion of melodies to issue forth within the coming weeks.