What best describes a steady beat in music

C. Underlying pulse of a piece of music.
Examples:Music written for a marching band may have a signature of 4/4, which means that four quarter-notes are specified n each bar.
On the other hand, music written for waltzing may have a signature of 3/4, which means that three quarter-notes are specified for each bar.
A metronome is often used during music lessons to teach the student how to observe the number of beats in a bar.

Italian composer who wrote 39 operas, as well as some sacred music, songs, chamber music and piano pieces.