However, there are many *types* of flutes, and some of them have proper nouns:
* Piccolo: A small flute with a high pitch.
* Alto Flute: A flute with a lower pitch than the standard flute.
* Bass Flute: A flute with a very low pitch.
* Contrabass Flute: An even lower pitched flute than the bass flute.
You could also use the name of a specific brand or model of flute as a proper noun, such as:
* Yamaha YFL-211
* Gemeinhardt 2SP
So, while "flute" itself isn't a proper noun, there are many *types* of flutes and *brands* of flutes that do have proper nouns.