Everyone has a different mindset or space that they like to get into when writing, and music / sounds are a big part of that.
There have been several scientific studies into music and productivity, the article linked below is a good read and provides a nice overview of research conducted.
The consensus of most of the studies being that music can improve your efficiency and even happiness while doing work / writing / blogging, but you have to ensure that its not also distracting you, and therefore its recommended that you listen to music without lyrics.
If I am trying to concentrate I will 90% of the time go for ambient sounds over music (luckily these have also been found to be helpful in boosting productivity and focus) – I will bravely and briefly point towards ASMR here – I use many of the ASMR videos on youtube not as relaxing aids but for focus, when I need to get something done.
However, I think especially related to writing, its not always about just being more productive. Its also about using music to evoke a mood, which can help you tap into those emotions during writing.
Again this might not just be about tapping into emotions but could also be getting into a headspace of a setting e.g. listening to music that relates to the timeline of your novel if your writing something historical or even if its set in the 80’s and therefore you listen to 80’s classics on repeat. I highly recommend that if your writing a fantasy novel that you go take a listen to ‘Two Steps from Hell’.
There are several example of books with ‘listening’ lists which I think is a beautiful idea.
Rachel Caine who wrote the Morganville series, published a track list at the back of the books to encourage people to listen along while reading. Being able to listen to what the author was taking in while they were writing can add another dimension to the piece of work.
The youtube link below is a brilliant example of an author using music to inspire scenes or sections of a novel she has written – I love the way she can clearly visualize each part of the scene it relates to as she goes through the track list.
I think as a last note it really comes down to what your preference is, if you find music distracting and always have then I don’t think that a scientific study telling you that it increases creativity and focus is really going to change that.
However if you are lucky enough to be able to use music to imagine scenes and feel your characters emotions then why would you not!
Everyone creates in there own way – are you a silence lover or someone who loves sounds while writing?