Until the early 80's I listened to nothing but rock and had a crisis -- rock was becoming boring. The solution: try something different. It turns out there's a whole world out there. I still love my old rock (still have and listen to my old albums from the late 60's - 70's) and some new, but I've come to love all sorts of stuff -- classical, opera, Indian and other "world" music, early blues/country.The are plenty of classical and opera primers, so I'll leave that alone, but a few other starter suggestions:
Indian -- Anthology of World Music: North Indian Classical Music; Anything by Ali Akbar Khan
Pakistan -- Anything by Nusrat Fateh Ali Khan
Old Time Country/Folk/Blues -- Anthology of American Folk Music (the Harry Smith edition); The Bristol Sessions; Times Ain't Like They Used to Be [start with Volume II]
Happy listening!