Sebastian Mayer [SEP] voice type
Sebastian Mayer
(Friedrich) Sebastian Mayer (actually Meier, 1773 – 9 May 1835) was a bass singer and stage director of the Classical era.
Life.
Mayer was born at Benediktbeuern. In 1793, he joined the theater company of Emanuel Schikaneder.
On 23 December 1797, he became the second husband of Josepha (Weber) Hofer, the sister of Constanze Mozart. Constanze was the widow of Mozart, who had died in 1791. Mayer's best man at this wedding was Emanuel Schikaneder.
Bach as "small" voices, voice types with certain characteristics: he names Peter Kooij and Dorothee Mields as examples of that voice type. 
By contrast, a number of 21st-century Bach conductors have instead accepted Joshua Rifkin's arguments that most of Johann Sebastian Bach's choral music was performed with only one singer per voice part.
Sources.
- Malcolm Boyd. "Bach". Oxford University Press, 2006.