a silly thing that I do

I like to drum along with my fingers when listening to music. But not in a "just tapping to the beat" kind of way. Instead, I pretend to play some imaginary instrument, probably one with keys ... so something like a piano or an accordion, depending on the orientation. There are no hard rules, but over the time, some conventions have emerged. For example, for chord progressions, I tap two fingers at the same time for each one, but leave out one in the middle, so "thumb-middle - index-ring - middle-pinky" and so on. For quick melodies, I do the same alternating pattern, but with only one finger at a time. Single-finger tapping in the regular order is for scale-like movements etc. This habit goes way back - it started as a finger exercise when I was still playing an instrument. Eventually, I stopped doing that, and it instead became a way to "engage" with music when I can't whistle, sing or dance along. I only do these things at home, when I'm by myself. But sometimes, when I'm out and…