The “Treble” is a woodwind instrument, like a recorder, made from long metal piping, a recorder mouthpiece and pink paint.
It is a member of the woodwind family because blowing air into the instrument causes it to vibrate, producing its sound.
Holes are drilled into the instrument to allow it to produce different pitches.
When your fingers cover more holes, the instrument produces a low sound. The less holes your fingers cover, the higher the sound.