Kalmar "C clef" alama ce ta kida da aka yi amfani da ita a cikin waƙa don nuna matsayi na C na tsakiya akan ma'aikata. C clef yana kama da harafi mai salo "C" kuma an sanya shi akan layin ma'aikata don nuna matsayin bayanin kula C. Akwai nau'ikan C clefs iri-iri, gami da soprano, mezzo-soprano/alto, tenor, da baritone. /Bass clefs, kowanne daga cikinsu ana amfani dashi don nuna matsayin tsakiyar C akan layin ma'aikata daban.