Time signature The time signature of a piece of music indicates how many beats are in each bar. A time signature allows a musician to count a steady beat while playing a piece. The time signature is written at the beginning of the staff . It comes after the clef and key signatures. You may find certain pieces of music have include changes to different time signatures. This will be marked on the sheet music, so always check through a piece of music to ensure you are aware of any changes of time signature it might have. Metronome mark A composer may include a metronome mark to indicate the tempo - how fast or slow the music should be played. For example, the metronome mark above tells you there are 80 crotchet beats per minute. Key signatures The key signature tells you which notes should be played as sharps or flats throughout a piece of music and therefore what key the piece should be played in. The examples above ...