What a friend calls "trancing out" -- when you listen to music while doing some repetitive task. It's not meditation. Meditation is focused. Focusing on the task at hand is not trancing out. Trancing out is escapist. The premise is that the task at hand is too boring for your entire attention. It's not really a trance; it's just doing more than one thing at a time. In meditation, the beginner focuses mainly on the breath, which can be considered boring, if you must think that way. Do you work on detailed tasks without trancing out? Does your mind wander when the task hits a repetitive point? That's the whole point of focusing on the breath, the simplest, most repetitive thing we do, while keeping the mind focused. Once you have the focus, you can have music playing and not trance out while you work, or write. The test is this: do you feel the same way with or without the music?
For me, cooking is a better example than writing. Cooking is a repetitive task which I find neutral-to-pleasant, although time-consuming. When I am cooking, I either remember to play music or I don't, but either way, I feel the same focus while washing and chopping veggies, and timing the addition of ingredients.
Some writers like to have music playing while they write. Many do not. I'm of the silence is best opinion, but I do occasionally play music while I write or revise. When it gets distracting it has to go. I don't usually listen to music while reading, either.
"Immersion in the life of the world, a willingness to be inhabited by and to speak for others, including those beyond the realm of the human, these are the practices not just of the bodhisattva but of the writer." --Jane Hirshfield