Variations in bass range

The low extreme for basses is generally C2 (two Cs below middle C). However, several extreme bass singers are able to reach much lower than this.
Within opera, the lowest note in the standard bass repertoire is D2 (Osmin), but few roles fall below F2. Although Osmin's note is the lowest 'demanded' in the operatic repertoire, lower notes are heard, both written and unwritten: for example, it is traditional for basses to interpolate a low C in the duet "Ich gehe doch rathe ich dir" in the same opera. Other optional or traditional low Cs and Ds are sung. The high extreme: a few bass roles in the standard repertoire call for a high F♯ or G (F♯4 and G4, the one above middle C), but few roles go over F4. In the operatic bass repertoire, the highest note is a G♯4 (The Barber in The Nose by Shostakovich); the aria "Fra l'ombre e gl'orori" in Handel's cantata Aci, Galatea e Polifemo calls for an A4.
Cultural influence and individual variation create a wide variation in range and quality of bass singers. Parts for basses have included notes as low as the B-flat two octaves and a tone below middle C (B♭1), for example in Gustav Mahler's Symphony No. 2 and the Rachmaninov Vespers, A below that in Frederik Magle's symphonic suite Cantabile, G below that (e.g. Measure 76 of Ne otverzhi mene by Pavel Chesnokov) or F below those in Kheruvimskaya pesn (Song of Cherubim) by Krzysztof Penderecki. Many basses have trouble reaching those notes, and the use of them in works by Slavic composers has led to the colloquial term "Russian bass" for an exceptionally deep-ranged basso profondo who can easily sing these notes. Some traditional Russian religious music calls for A2 (110 Hz) drone singing, which is doubled by A1 (55 Hz) in the rare occasion that a choir includes exceptionally gifted singers who can produce this very low human voice pitch.
Many British composers such as Benjamin Britten have written parts for bass (such as the first movement of his choral work Rejoice in the Lamb) that center far higher than the bass tessitura as implied by the clef.^[1] The Harvard Dictionary of Music defines the range as being from the E below low C to middle C (i.e. E2–C4).^[2]
In choral music, voices are subdivided into first bass and second bass, no distinction being made between bass and baritone voices, in contrast to the three-fold (tenor–baritone–bass) categorization of solo voices. The exception is in arrangements for male choir (TTBB) and barbershop quartets (TLBB), which sometimes label the lowest two parts