So, I play some music for my parents, who listen to mostly classical/romantic era music. I play the london philharmonic version of stairway to heaven for them, and an acustic solo by Jimmy page (which was composed by him) for them. After hearing both pieces, they think they've heard some unkown work by a famous classical musician. Point of the unofficial study is; Quality of music hasn't changed in the least as long as music as existed. It's the TASTE in music, that has actually changed.