Nice! I’m a piano accordion player and I’m wondering how the bass works. there’s a low bass sound that’s mostly not present in the beginning and end. How is that played?
You're still hearing the chord button. These diatonic accordions often cheat by omitting the third in the chord so they can play minor and major keys with the same button (so essentially a power chord). That's why it sounds gentle and not like a full chord. You can see a mod like this in Lester Baileys "How to hot rod a Hohner" video series.
