She wrote the song and sang it another person Justin Guarini also sang it. On the first season of American Idol too
The answer is motif :) any reoccurring theme, pattern, idea, image etc. in a work applies to this.
for example, an artist that includes flowers in across all of their work (or a series of it) would be depicting a floral motif. I hope this helps!!
It is not the same style, just similar (:
