"Low C" refers to a specific musical note that is two octaves below middle C on a piano. It is often used in various musical compositions and is significant in the context of bass instruments, such as the bass guitar and tuba, where deeper tones are essential for creating a rich sound. In the context of vocal music, "Low C" is particularly important for bass singers, as it represents one of the lowest notes they can sing. This note is crucial for establishing the harmonic foundation in choral arrangements and orchestral works, contributing to the overall depth of the music.