In mid 70’s, I played daily after yoga in Meiji Park, Tokyo
Yes! This is true for the Buddhist Honkyoku. What you do need, however, is to pay attention. Yet, you don’t even need to do that. Of course, if you don’t really listen to what you are doing, you will not enjoy what you are doing. This makes playing Honkyoku a practical means of training watchfulness in non-stimulating situations. Paying attention when there are no environmental conditions to trigger need, desire, fear, or worry is most useful, I find. The bonus: your improved listening ability (mindful watching) naturally taps into your hidden musical talent, much of which centers around listening!
By the way, playing honkyoku by heart is the most direct way of “playing music without playing music”. This is Taoist wéi wú wéi (为无为) or “doing without doing”. (see chapter 3)