For me it's about the feel / style of the music. A piece can be played on a flute and be ultra-modern, so it's not the instrument. And if I'm going to a concert that bills itself as having relaxing classical music I wouldn't mind if they had modern-written pieces in that same style. I understand that the word initially had a specific meaning, but meanings change over time. Blues music as a genre has changed over time. I think that's a good thing.