One of my Texas Tech faculty colleagues showed me this article from the July 15 American Way magazine (from American Airlines) on Boston University law professor Mark Pettit, Jr.
Professor Pettit has gained national attention for -- you guessed it -- singing to his law classes. It appears from the article that Pettit's lyric material comes primarily from his students. Some students submit poems instead of song lyrics.
I've had a few students write their own lyrics and, when they do, they sing them, too. When students in a class are able to write a full set of course-relevant lyrics for a song, it suggests to me that they have great mental fluency with course concepts.