Thankyou for your thoughtful responses to my question.
I’d like to think that a diversity of reasons for practicing yoga were allowed. I do yoga because I find fun in it - and silence and calm and relief. I initially turned to it as a refuge from my corporate job and have stuck with it for a plethora of other reasons. Frankly, if I didn’t find it fun, I wouldn’t do it. It would be more productive for me to clean my house an hour each day instead.
While I respect others that pursue yoga for spiritual reasons, I can’t see any reason not to extend that same respect to those that might pursue it to get fit, lose weight or stay looking fabulous - however we may differ from such motivations.
It could be overstimulation of my nervous system that’s causing me to want music… or it could be that I’m from a school of thought that believes no God but that if God exists, then God appears in the form of mountains, skies and music. It’s not that I don’t feel anything without music. It’s just that I feel more when it’s there. Equally, if I could practice where the air smells of trees rather than Beijing traffic, I’d find more joy in the practice.
That said, I will continue to reflect and thank you all 
Happy and fun practising!
Y