I may have created the impression in my last post that I think music has to be dark and/or tragic to be deep and profound. This is not the case, not at all. The music of J. S. Bach, far and away my favorite composer, is often quite joyous and profound at the same time. To give just a few examples out of a great many: the 1st and 3rd movements of the Italian "concerto (in spite of the title, a solo keyboard work, often played on the piano today), the Prelude in E major from the unaccompanied violin partita in E major (often played quite effectively on the classical guitar also), many of the movements from the Goldberg Variations, and the opening chorus of the cantata "Wachtet Auf". Now, to be sure, many of his works are dark, indeed, "Gothic", almost in the modern sense of the word. A popular example would be the famous Toccata and Fugue in D minor---a piece that has been used in horror movies, and is in the German organ tradition that Bach acquired partly from the great Herr Dietrich Buxtehude.
Examples of tragic pieces abound in Bach's output. Examples would be a significant portion of the Chaconne, also for solo violin, and portions of the St. Matthew Passion.
Then there are abstract pieces, which are perhaps also highly emotional and esthetically appealing to those of us with mathematical orientations, such as the Art of the Fugue, The Musical Offering, and a significant fraction of the Well Tempered Clavier. Some of this latter class of works could almost be heard as being contemporary, 20th century music.
As Kenneth Clark has pointed out in his celebrated "Civilization" program, Bach's art was "religious art", and it is probably helpful to understand some of Bach's Lutheran theology (but not necessarily to share in his beliefs) to fully appreciate his music. Maybe not mandatory---I like to think it is not---but likely it enhances the rapport to some degree.
However, it was notable, and surprising to some, that Richard Dawkins, today a prominent atheist, listed the St. Matthew Passion as the one work he would want to listen to if he could only take one to a deserted island. I might pick that too, only I would hate to have to pick only one work....could I maybe take a thousand?