 The contrabassoon, double bass, and electric bass sound an octave lower than the written pitch; no notation is usually made of this fact, but some composers/publishers will place an "8" beneath the clef for these instruments on the conductor's full score to differentiate from instruments that naturally sound within the clef (see "Octave clefs" below).† When the F-clef is placed on the fifth line, it is called the sub-bass clef.It is identical to the treble clef transposed down 2 octaves.