A staff, also called a stave, is the foundation for writing notation in Western music. It consists of a set of five horizontal lines and four spaces in which notes and other symbols are drawn or printed. Notes with higher pitches have higher positions on the staff and notes with lower pitches have lower positions. Notes higher or lower than those accommodated by the lines and spaces in staves are placed on or between ledger lines, which are short lines drawn above or below the staff. The one exception is for unpitched percussion instruments, for which each line or space indicates a specified instrument rather than a pitch.
Piano music notation uses two staves. The upper one, the treble staff, is for the right hand and the lower one, the bass staff, is for the left hand. In scores with a small number of instruments, such as chamber music, each instrument will typically have its own staff. In full scores, each type of instrument will usually have its own staff, such as one for the flutes, one for the oboes, and one for the violas. The main exceptions are the horns, which typically have two, and the violins which have one each for the first violins and the second violins, as well as a third for a solo violin if it is used.