To give you an example, Kant is reason, obligation, morality, reason, obligation, reason, reason, reason, obligation, morality. He always harps on using disinterested reason as the foundation of a universal morality, and basically divorces our passions from our duties. In the same time frame, you have Bach, who writes very mechanical, intricate works that have very strong tonality (basically a very scale-based way of writing step-wise melodies around a clearly defined "tonic" tone)...so the two are strikingly similar. Kant is basically reams and reams of intricate logical constructions around a set of very simple principles, as Bach is pages and pages of noodling around very firmly grounded tonal bases. Other composers are a lot less ornate, more fluid, more amorphous with the tonality, etc. that inspire more romantic connections. Some composers/philosophers are more optimistic, some tragic, etc.
Bach doesn't seem optimistic or tragic. He seems like he has a very strict notion of duty and penance in his music. Check out his presentation of his masterful Brandenberg Concerti:
"As I had the good fortune a few years ago to be heard by Your Royal Highness, at Your Highness's commands, and as I noticed then that Your Highness took some pleasure in the little talents which Heaven has given me for Music, and as in taking Leave of Your Royal Highness, Your Highness deigned to honour me with the command to send Your Highness some pieces of my Composition: I have in accordance with Your Highness's most gracious orders taken the liberty of rendering my most humble duty to Your Royal Highness with the present Concertos, which I have adapted to several instruments; begging Your Highness most humbly not to judge their imperfection with the rigor of that discriminating and sensitive taste, which everyone knows Him to have for musical works, but rather to take into benign Consideration the profound respect and the most humble obedience which I thus attempt to show Him."
Kinda humble there...just like Kant's attempt to humble us about the limits of our reason, the absolute nature of our duty, and our obligation to strive towards a pefectly good will (compared to the imperfect, lowly one we have now).