After I read he report I consciously gave attention to the music of Mozart and others like Bach and Beethoven. It's not easy to classify if only Mozart's music has repetitive melodies and others' don't, but still there's no doubt that in many of Mozart's compositions a particular melody flows around throughout the piece, very much like a theme music or like a hymn.
Here are some examples.
String Quartet No. 17 in B flat major ('Hunt'), K. 458