eli5: why do we know a note is off key even when we’ve never heard the piece of music before?

Question

Whenever I hear someone play an instrument, I can always tell when they’ve played the wrong note even if it’s my first time hearing it, why is that?

In: Other

Answer 1

Because you have learnt it from a young age. Try and listen to traditional Indian music, you won’t know if anything is off-tune, trust me!