Stupid question. I haven’ thought about this for a long time… but why should a reed of a fixed length even be able to produce 2-3 different notes? After all, in the end, we’re just inhaling… drawing the air through the hole in one direction.
I do recall once looking at a stripped down harp in a mirror as I played and noticed that the two reeds in a single hole were vibrating. Maybe I dreamt that part. It might have been 30 years ago.
Is there some sort of interplay between the reeds that creates the different notes?
What are the physics involved?