合唱

がっしょう · gasshou · JLPT N1 · noun

chorus

合 — 乛 (lid/roof) + 口 (mouth)
Originally a pictograph of a lidded vessel — a cover (亼) closing over an opening (口) — giving the core sense of 'come together, join, fit.' From 'fit/match' it extended to 'combine, unite, agree' and to measure-word uses. The reading hé reflects this 'joining' meaning.

唱 — mouth 口 + 昌 (bright/prosperous, phonetic)
唱 is a semantic-phonetic compound. The mouth radical 口 signals an action done with the voice, while 昌 supplies the sound and originally meant 'bright' or 'flourishing.' Together they came to mean 'to sing' or 'lead in chanting,' extending to 'call out' or 'proclaim.'

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