You might regard the title of this tune to be "Canon", but in fact, canon is a contrapuntal compositional technique just as fugue/gigue by Bach (who happened to be one of my least favorite composers as a child LOL). This tune in D major by German composer Johann Pachelbel is considered to be the most famous and well-flowed canon. and it has been "variationed" by numerous pianist, including George Winston version, and Asian movie <My Sassy Girl> (BTW don't freak out by the movie title, the girl is actually pretty and nice).