It's ok, it's a positive thing as chanting and mantra's have long been forms of "meditation/relaxation of the mind". Actually, a documentary was done on George Harrison who embraced this form of "spirituality" and realized the significance of how it calms the mind and spirit. You should look that documentary up because there are good take away thoughts you can get from it.

It doesn't really matter what song you choose Mowtown, if it brings you a calm, then that is what is important. Our brains "like" things that are repetitive, as I mentioned, it's predictable and helps the brain wind down. Our brains "love" familiar repetitive things, that is why "change" is so upsetting because it requires more frontal lobe work until a pattern is in place again.

That is one of the core challenges that comes with PTSD because a trauma "changes" our overall pattern that brings us that sense of rhythm and control. That is why we often have an strong urge for change from how we lived a previous rhythm. That is part of the "just" we had that was manageable to where something "traumatic" happened that changed that pattern we adapted that we were capable of managing. That is why retirement can become fatal to people because they were so used to a daily rhythm that drastically changes, "unless" a person slowly prepares a plan for a future rhythm they can easily slip into and adapt as a new rhythm they "just" slip into everyday, and some people never "really" retire because they like the rhythm of their life as it is.

The best way for you to gradually gain is to develop a rhythm agreeable to you, it doesn't have to include being the best at anything either, it's just adapting an activity that you can repeat that you benefit from and enjoy on a personal level. Well, this song you use is just something you find "agreeable" to "you", it is familiar and predictable, it doesn't have to have any "more" meaning than just that.