What they do, to get their doctorates, is find a composer or a piece of music trivia and find out all there is to know about it and what relates to it. If you have a love of librarys and manuscripts and understand what the term "primary source" means (I write here about incunabula fairly often), then this stuff is right up your alley.
Anyway, I really do remember the first time I heard this piece - 1972, Lexington, Ky, the LeMay String Quartet - no kidding. There was a TV commercial that came out that used a snipet from it and that launched its career. The Wiki article is what I would consider a scholarly work written by a musicologist....possibly an extract from the dissertation...but well footnoted. This might well be 4 months hard work. Back 40 years ago it was 2 years work just because we had no Internet and everything was by snail mail or inter-library loan.
I just posted it previously as "wedding music" as that is where this canon is often played now - along with Mercedes Benz commercials. It isn't a toe tapper but it IS so well crafted. Just so you know a canon is a "rule"...not something that goes "boom"... and it has rigid construction...think of a complex "row row row your boat"..."D" is the key - but that is music theory...generally it means that the primary chord in the piece..the start and ending notes so to speak (much more technical than that but this is music 101 at 6am) centers around a chord built on the note "D"...that's the white key on the piano between the set of two black keys... anyway...follow along..