In my formative years, while most of my contemporaries and friends cut their teeth, well, ears, rather, on Grace Slick, Jimi Hendrix and Jim Morrison, I was parsing the niceties of each and every one of Mozart's piano concertos, as music, not to play. (I wasn't that good at the piano; still not, really). Later I looked further back, to Bach, to the great Heinrich Schütz (still hardly a household name), to Josquin, Ockeghem, Dufay.
So that accounts for the following obscure judgments, one actually rather commonplace among classical music aficionados, the second slightly less so perhaps, and the third rarely mentioned.
1. Had Mozart not had kidney disease and died at barely 36, (and instead lived to a nice, ripe old age) he would have eclipsed Beethoven and be thought of today as the greatest composer ever, with the sole possible exception of Bach. (There are some who think so anyway).
2. Had Schubert not had syphilis and died at barely 31, (ditto) he would have eclipsed Beethoven and be thought of today as the greatest composer of the 19th century.
3. Had Orlando Gibbons not suffered an aneurysm (or something like it) at about the same age that Mozart lived to, in 1625, (ditto) he would have eclipsed John Dowland and be generally thought of as the greatest English composer ever, and the equal of the other titans of the 17th century, Monteverdi and Schütz.
I realize these kinds of contrafactuals are pretty meaningless, and they seem to annoy some rather persnickety folks, but I find them irresistible now and then.