I find myself in an odd position. My pre-Orthodox days were filled with music, yes, but it was entirely classical and jazz with little rock, as I was a semi-professional trombonist. I became interested in popular music only a year or so before the year that saw me leave behind the trombone and embracing Orthodoxy.
The opinion I have formed without researching Holy Tradition is this: Secular music, art, literature(hereafter referred to as "art", etc can be a good thing and even show some truth. It can be an excellent stepping stone into finding faith for many secular folks. I can see two problems:
"Art" that speaks to the lowest of human depravity or is even at enmity with The Church. For example Marylin Manson, Anton Le Vey, and that man who made the painting of the Theotokos with elephant dung.
That when those of us who were former secularists find the truth of Orthodoxy, we spend time with "art" that while not bad for us, obscures us from more holy endeavors.
Number two is the more subtle and the more dangerous I believe. I still enjoy rock music, literature, and movies, but I look forward to them slowly fading from my life. It seems that many people here in America define their lives by entertainment. In being an example to turn from the world, I think that we should lessen our dependancy on secular entertainment to the degree that we are able. A "cold-turkey" approach may not be best though.