This may sound jaded, but in my honest opinion this isn't a solvable problem
(not easily, anyway). Classical music requires mental engagement on a level that modern music does not. If you don't engage intellectually, its power is lost on most people. Music today is like mainlining endorphins and dopamine by comparison, whereas classical music is more akin to getting the endorphins from a good book, a good run, etc. except you have to generate the internal "movie." In other words, it takes effort whereas modern music doesn't. Just my two cents. The only way I've been able to encourage others to appreciate classical, in a way that actually sticks with them to where they seek it on their own, is either 1. Take them to concerts where they have to sit and pay attention, and especially take them to any lecture beforehand where the conductor discusses the history and intention behind the work, 2. Find a piece of music that addresses a specific type of emotion and have the listener close their eyes and imagine something that is complimentary to the music (i.e. Chopin Prelude in E Minor and ask them to imagine someone they love who passed on while listening) or 3. LSD....no, I'm not kidding. It does change people's view of Classical. Erm...I learned that from a friend.