The best answer here would be pencil.
Artists use pencil to make sketches and create studies. They then use these sketches and studies to create their final larger piece. They use pencil because it's quick, can be corrected, lightweight and easy to use. Before pencils artists would make charcoal drawings but once we had pencils it made sense to use them as they aren't messy like charcoal.
The answer among these works that features a flute with a delicate, "breathy" sound in a relatively high register is Concerto for Orchestra by Bela Bartok.
