The fingering of the contrabassoon is different from that of the bassoon, most evident at the register change (omitting the left first finger, where one would half-hole on bassoon) and in the high range. Compared with the bassoon, the contrabassoon has much greater difficulty producing notes with stability and projection in the (written) range corresponding to the top octave on bassoon. Its fingerings for this register are also completely different to the bassoon, because the contrabassoon has a different harmonic series and a simpler fingering system. Scoring for it very seldom calls for notes above written-pitch F or G above the bass staff, and the higher clefs are therefore seldom required.