What about this as the jump off point for a discussion about vocal pedagogy and genre comparisons? This impressionist is named Christina Blanco and her performances, especially “Total Eclipse of the Heart,” provide an amazing study on genre and vocal idiosyncrasies. These town examples feature piano accompaniments that change to fit the vocal stylings. Image using this to discuss how differing vocal styles and accompaniment patterns can substantially change the mood and/or character of a piece. Also, discuss the vocal techniques employed here so you students might be able to develop their own vocal styles.
Also, consider Ariana Grande's vocal impressions:
Rob Cantor's impressions are worth investigating, too: