Are harmonics and muted notes only possible on string instruments like Guitars and Violins? Are they possible on pianos, organs, flutes, horns, harps or brass instruments?
By harmonics I meant those sounds you get when you pick a string lightly on the 12 fret for instance and you get that nice shining timbre.
Brass instruments in particular will only work due to harmonics! Listen to a bugle call - each and every note played is actually a harmonic!A trumpet only has the valves so it can play the in-between notes - those that a bugle cannot play.
Any stringed instrument that the strings are accessible to touch can produce audible harmonics, as you know already.
Muted notes are something rather different. Brass instruments like trumpet and trombone use mutes, but they're rather different in the way they mute notes. Pianos can mute, too - there's sometimes a practice pedal that moves a curtain of material over the strings, so the hammers hit it as they hit the strings. I suppose you could even say the 'soft' pedal is a kind of mute, too.
The Harp definitely has harmonics as well. There is a famous part of La Boheme that has a harp playing harmonics.
As a general rule, there are two things that are meant by saying the word harmonic. There is the botoon or overtone that is sometimes played by touching certain stringed instruments at certain places while playing.
More generally a harmonic is some tone that is played over some sort of base tone. Think of what a harmoniser pedal is on electric guitar, it is a pedal that takes the base tone of your guitar and plays another tone over it, a certain interval.
So bringing it back to your question can an Organ play harmonics? An organ may consist of a number of harmonics, it is not all that uncommon to multiple pipes blowing at a time and these pipes may all add a harmonic texture to the music.
Can a harp play harmonics, yes as the video demonstrates? I don't know enough of the working of brass instruments or flutes so I will leave those two for other answers.
