I have seen similar questions regarding this but containing answers that somewhat disagree with each other which makes it hard for me to understand this.
My question is mainly about when plucking a string instrument at the end side of it, not in the middle. From several slowmotion videos, including this one and this one, I can see that this creates a single propagating wave that reflects back and forth.
If there is no periodic plucking, there is no way that this single propagating wave would interfere with itself to produce standing waves and thus harmonics. And yet, I keep reading that plucking a string instrument (once) would produce (a mixture of) harmonics. How is this possible with a single propagating wave that can not interfere with itself? Are there other conditions, other than interfering propagating waves, that produce harmonics?