Erik...My knowledge of and experience with bluegrass is virtually nonexistent, so I can’t comment on it even in fun. However, I used to mock Mozart by referring to his "snuff box" music. Then, when one day out of nowhere, I found myself attracted to his chamber music, I experienced a sense of cognitive dissonance. I had to tell my mind it was okay to have positive feelings about Mozart despite all the years I had previously felt otherwise. Frankly, I’m still not especially fond of his symphonies, though I do enjoy his piano concertos.
hfiman...Of course, Shostakovich is an entrely different kettle of fish relative to Mozart. Though not quite in the same company with my personal favorites, I do admit he can certainly press other buttons of satisfaction for me. That "complicated psyche" (as you say), with its dark, probing aspects and occasional shafts of sunlit hope can frequently have a riveting effect on the mind and spirit. There was a time when, perhaps like some others, I found his music too dreary. Then, one day, as with Mozart, my feelings were transformed. I was suddenly able to experience Shostakovich in a new and fascinating way. My favorite among his symphonies are the 4th, with Kondrashin (lp) and Jarvi (cd), and the 7th, with Kondrashin (lp) conducting. I also enjoy a fair portion of his chamber music.