Year 8 have been describing timbre with words like pure, breathy and bright, and the teacher wants them to see where those differences come from. A phone running phyphox's audio spectrum experiment sits on a stand at the front, streaming its graph to the board through phyphox's remote access on the school wifi. The teacher sounds a 440 Hz tuning fork, plays the same A on a flute, and then a Year 12 violinist plays it on the open A string. Students watch a single peak for the tuning fork, a strong fundamental with a few weak harmonics for the flute, and a long row of evenly spaced peaks at 880, 1,320 and 1,760 Hz and beyond for the violin; when the teacher sings one A on 'ah' and then 'ee', the fundamental stays put while different harmonics grow and shrink. Students sketch each spectrum in their books, label it with the timbre words from last lesson, and write a sentence explaining why two instruments playing the same pitch never sound the same.
This page is one of a growing set of PICRAT examples by cell, subject and grade. Page maintained by Andy Perryer.