This… honestly just made my heart hurt. 
How can one determine what is considered “service to self” or “service to others” when it comes to musical expression? It feels like in order to do that, a lot of judgement would have to be placed upon what sort of musical expression promotes what sort of feelings. Most feelings are based on conditioning, life experiences and biases. Where do the biases come from? Is it from the planetary energy? The societal energy? Is it life conditioning? Is it how you evolved to process emotions? There are so many factors that can come into play when you start picking apart source energy with logic. I guarantee you’ll never find an answer you’ll be satisfied with. Now, if you use your heart, you’ll feel all the healing you’ll ever need from any musical source.
Yes, all music is healing. Making music is healing. I’ve spent years around musicians and the amount of healing I did just being in their presence spoke volumes to me. Pun intended. If you’ve ever sat next to anyone playing the drums, you’d understand. 
Even the presence of simplistic tones can be healing. You could hear some random “boops” and “beeps” and it may bring a smile to your face because it reminds you of something that brings joy to your heart. Or you could just use it to inspire your imagination and come up with a little tune yourself. Even the rhythmic sounds of a construction site can create a beautiful melody if you can isolate the sounds and feel them intuitively.
Now that brings me to my next point. How about the evolution of one who makes music from the beginning of their journey to where they end up? Most people who make music don’t think, “Gee, I wanna be famous. How can I express myself creatively so I can sell my soul later?” No, they make music to heal, to express themselves and then, society puts its “rules” onto how they can “sell” their music and it gets warped at the end of the day. Maybe at one point there were more people who did this because how much “rock stars” were glorified. You can see the evolution in society as the way of treating musicians as “more than human” is becoming less and less of a thing and more original content from the heart is being favoured. Between that and music streaming, the way we can access music as a society has changed. Anyone with a YouTube channel and a good voice can create a following these days.
If you watch any musical documentary, no matter how famous, they are all human at the end of the day, trying their best to make good choices for their own lives. How can we know what it’s like to be them from the outside of their lives? In Pink’s documentary, “All I Know So Far,” she puts on these crazy arena shows then goes back to raising her kids. She says it’s “surreal.” Even the singers performing are aware (or mostly aware) of the impact of that kind of life is all a matter of perspective. I think this attitude keeps one more grounded than most.
How you look at and feel about music personally says a lot too. Perspective matters greatly.
As a good example, During Woodstock ‘99 (I just love how angry my generation was), the song “Break Stuff” by Limp Bizkit led to a riot. On the other hand, that song can be incredibly motivating if you perceive the energy in a specific way. It could be empowering, or it could be destructive. It’s how you perceive the music, not the musical express itself. I can’t speak for mob mentality though…
So I say no, music is not inherently following a polarity itself. It’s unbiased. It takes no sides. It is pure source. Did the music create the atmosphere that lead to the disaster that was Woodstock ‘99? No, it was ego and unbalanced masculine energy. That documentary says a lot, I’d recommend it to anyone who wants a closer look at what unbalanced energy in the music world looks like.
I do believe there are musical expressions that may be made with more sinister intentions, ie. to control and manipulate, but I feel like if you access your heart energy center, you’ll be able to feel that immediately and your heart would be strong enough to know whether or not to walk away from that particular vibration.