Friction idiophones produce sound by rubbing, and include which instruments?

• A. The Musical Saw And Glass Harmonica
• B. The Xylophone And Marimba
• C. The Snare Drum
• D. The Pan Flute

Answer: (A)

Friction idiophones produce sound by rubbing, which excites continuous vibrations through friction rather than by striking or plucking. The musical saw is played by sliding a bow or rubbing the blade with a finger to make it vibrate, yielding a sustained, singing pitch. The glass harmonica creates tone by rubbing wet fingers around the rims of glass bowls, also relying on friction to excite the glass. In contrast, the xylophone and marimba are struck instruments (sound from hitting wooden bars), the snare drum uses a vibrating drumhead (membranophone), and the pan flute produces sound from vibrating air in a column (aerophone). So the instruments that fit friction idiophones here are the Musical Saw and Glass Harmonica.