In computer science, a type class is a type system construct that supports ad hoc polymorphism.
 This is achieved by adding constraints to type variables in parametrically polymorphic types.
 Such a constraint typically involves a type class codice_1 and a type variable codice_2, and means that codice_2 can only be instantiated to a type whose members support the overloaded operations associated with codice_1.
Gotthold Schwarz (born 2 May 1952 in Zwickau) is a German bass-baritone singer and conductor.
 Based in Leipzig, he started as a member of the Thomanerchor and has conducted the Gewandhausorchester.
 He is the 17th Thomaskantor after Johann Sebastian Bach.
Metahistorical Romance is a term describing postmodern historical fiction, defined by Amy J. Elias in "Sublime Desire: History and Post-1960s Fiction."
 Elias defines metahistorical romance as a form of historical fiction continuing the legacy of historical romance inaugurated by Sir Walter Scott but also having ties to contemporary postmodern historiography.
 In particular, in metahistorical romance, poststructuralist play invokes the "historical sublime" as defined in the work of Hayden White.
 Metahistorical romance--such as Thomas Pynchon's novel "Mason & Dixon"--attempts to recuperate the sublime untouchability of the past, to reach History and know it, but paradoxically in the context of the political.
 As with the Kantian sublime, the postmodern historical sublime is not the grasp of the sublime object itself but a kind of ironic awareness of the inaccessibility of the sublime object.
 There is a yearning that resembles the yearning for mystical knowledge at the core of the search for the historical sublime, and thus the concept ties contemporary historical fiction to a literary history (that of the historical novel), a type of historiography (postmodern, post-"Annales" historiography), and a spiritual questing.
 Elias argues that the postmodern imagination confronts the historical sublime rather than represses it; confronts it as repetition and deferral; seeks sublime History but simultaneously has lost faith in the storytelling needed to do so; and consequently has ties to, but reverses the dominant of, the traditional Anglo-American historical novel.
 The term "metahistorical romance" also builds upon work by Linda Hutcheon, whose term "historiographic metafiction" described the ironic stance of contemporary historical fiction.
Heike Maria Kumlin is a German soprano.
 After studying opera in Aachen, she attended the master classes of Edith Mathis, Judith Beckmann, Peter Schreier and Christoph Prégardien.
 Kumlin has since performed with the Thomanerchor and the Gewandhausorchester, and is renowned for singing works by composers such as Bach, Handel and Mozart.
 In 2003 she recorded Bach's cantata "O heilges Geist- und Wasserbad", BWV 165 conducted by Gotthold Schwarz, with Alexandra Röseler and Martin Krumbiegel.
A bass-baritone is a high-lying bass or low-lying "classical" baritone voice type which shares certain qualities with the true baritone voice.
 The term arose in the late 19th century to describe the particular type of voice required to sing three Wagnerian roles: the Dutchman in "Der fliegende Holländer", Wotan/Der Wanderer in the "Ring Cycle" and Hans Sachs in "Die Meistersinger von Nürnberg".
 Wagner labelled these roles as "Hoher Bass" ("high bass")—see fach for more details.
In computer science, an opaque data type is a data type whose concrete data structure is not defined in an interface.
 This enforces information hiding, since its values can only be manipulated by calling subroutines that have access to the missing information.
 The concrete representation of the type is hidden from its users, and the visible implementation is incomplete.
 A data type whose representation is visible is called transparent.
 Opaque data types are frequently used to implement abstract data types.
In type theory, a kind of foundation of mathematics, a quotient type is an algebraic data type that represents a type whose equality relation has been redefined by a given equivalence relation such that the elements of the type are partitioned into a set of equivalence classes whose cardinality is less than or equal to that of the base type.
 Just as product types and sum types are analogous to the cartesian product and disjoint sum of abstract algebraic structures, quotient types reflect the concept of set-theoretic quotients, sets whose elements are surjectively partitioned into equivalence classes by a given equivalence relation on the set.
 Algebraic structures whose underlying set is a quotient are also termed quotients.
 Examples of such quotient structures include quotient sets, groups, rings, categories and, in topology, quotient spaces. For example, formula_1, the rational numbers, is the quotient ring – or "field of fractions" – of formula_2, the integers.
Alexandra Röseler is a German mezzo-soprano and pianist.
 She won the 1988 Schiller Prize of the Nationale Forschungs- und Gedenkstätten der klassischen Deutschen Literatur Weimar.
 After a period studying at the University of Magdeburg from 1992, she began a career as a concert pianist, performing for example Schumann's Piano Concerto.
 By the late 1990s, she had furthered her studies, studying vocal performance under Regina Werner at the University of Music and Theatre in Leipzig.
 Röseler has since appeared in numerous recordings and recitals of baroque music as a mezzo-soprano and alto and has performed regularly with the Thomanerchor.
 In 2003 she recorded Bach's cantata, "O heilges Geist- und Wasserbad", BWV 165, with Gotthold Schwarz, Thomanerchor, Gewandhausorchester, Heike Kumlin  and Martin Krumbiegel, singing the alto part.
In computer science and logic, a dependent type is a type whose definition depends on a value.
 A "pair of integers" is a type.
 A "pair of integers where the second is greater than the first" is a dependent type because of the dependence on the value.
 It is an overlapping feature of type theory and type systems.
 In intuitionistic type theory, dependent types are used to encode logic's quantifiers like "for all" and "there exists".
 In functional programming languages like Agda, ATS, Coq, Epigram, Idris, and Shen, dependent types prevent bugs by allowing extremely expressive types.
A voice type is a particular human singing voice identified as having certain qualities or characteristics of vocal range, vocal weight, tessitura, vocal timbre, and vocal transition points ("passaggio"), such as breaks and lifts within the voice.
 Other considerations are physical characteristics, speech level, scientific testing, and vocal register.
 A singer's voice type is identified by a process known as voice classification, by which the human voice is evaluated and thereby designated into a particular voice type.
 The discipline of voice classification developed within European classical music and is not generally applicable to other forms of singing.
 Voice classification is often used within opera to associate possible roles with potential voices.
 Several different voice classification systems are available to identify voice types, including the German "Fach" system and the choral music system among many others; no system is universally applied or accepted.

Question: Gotthold Schwarz is of a voice type whose term arose when?
Answer: late 19th century