The violoncello ( VY-ə-lən-CHEL-oh, Italian pronunciation: [vjolonˈtʃɛllo]), commonly abbreviated as cello ( CHEL-oh), is a medium-low pitched bowed string instrument of the violin family. Its four strings are usually tuned in perfect fifths: from low to high, C2, G2, D3 and A3. The viola's four strings are each an octave higher. Music for the cello is generally written in the bass clef; the tenor clef and treble clef are used for higher-range passages.