a combination of a treble clef staff and a bass clef staff to form a two-staff set covering the most common range of pitches. This is used for keyboard music. middle c (C4) occupies the single ledger line between the staves: right in the middle.
The combination of a staff line notated in treble clef with one notated in bass clef. Used primarily in scoring for piano, and other keyboard instruments, this staff is also sometimes used to score vocal works, such as hymns.
The Grand Staff using both bass clef on the bottom and treble clef on top allows for four octaves of notation, counting the two high ledger lines for Soprano C and two ledger lines below bass clef for Deep C. Note, however, that more than two ledger lines may be used.