I saw someone change a liquid’s colour by playing a violin in the key of B major. How did that work?

Question: I saw someone change a liquid's colour by playing a violin in the key of B major. How did that work?
- Keywords:
  colour,
  liquid,
  state,
  violin
Asked by to Edward on 16 Jun 2014. This question was also asked by .
- Edward Hughes answered on 16 Jun 2014:
  
  I think I’m going to need more information to answer this one. Have you got a video? And do you know what the liquid was made of? I’d be inclined to say that this was probably a trick, but maybe it’s something clever to do with resonance.

Question: I saw someone change a liquid's colour by playing a violin in the key of B major. How did that work?