the bard's mistrustful eye at music

Perhaps because it was the most threatening alternative to playgoing (save bear baiting), Shakespeare seemed to talk some serious trash about the so-called universal language of music. 

There is, of course, the famous opening to Twelfth Night,

If music be the food of love, play on,

Give me excess of it, that surfeiting,

The appetite may sicken, and so die.

Ok, so this might not be strong enough to be called trash talking, but I was listening to Othello, and there's that great scene where the musicians are asked if they can play any music that cannot be heard, and if so to play to their heart's content. More examples if I happen to come across any.