Question: What differentiates Recitative from Arioso music style?

Context paragraphs:
Música sertaneja: Música sertaneja (] ) or Sertanejo (] ) is a music style that had its origins in the countryside of Brazil in the 1920s.  It is the most popular music style in Brazil, particularly throughout the southern/southeastern and center-western countryside Brazil.  Subgenres include "sertanejo de raiz", "sertanejo romântico", and "sertanejo universitário".

Accentus: Accentus (or Accentus Ecclesiasticus; Ecclesiastical accent) is a style of church music that emphasizes spoken word.  It is often contrasted with "concentus", an alternative style that emphasizes harmony.  The terms "accentus" and "concentus" were probably introduced by Andreas Ornithoparchus in his "Musicae Activae Micrologus", Leipzig, 1517. " "Concentus" might be chief ruler over all things that are sung...and "Accentus" over all things that are read," according to Ornithoparchus.  The style is also known as liturgical recitative, though it differs in some important ways from other types of recitative.

Arioso: In classical music, arioso ] (also aria parlante ] ) is a type of solo vocal piece, usually occurring in an opera or oratorio, falling somewhere between recitative and aria in style.  Literally, arioso means "airy".  The term arose in the 16th century along with the aforementioned styles and monody.  It is commonly confused with recitativo accompagnato.

Recitative: Recitative ( , also known by its Italian name "recitativo" (] )) is a style of delivery (much used in operas, oratorios, and cantatas) in which a singer is allowed to adopt the rhythms of ordinary speech.  Recitative does not repeat lines as formally composed songs do.  It resembles sung ordinary speech more than a formal musical composition.

Calliroe: The opera follows the usual pattern of "opera seria" of the time: "secco" recitative interlaced with "da capo" arias. Within this format Sacchini introduced strong dramatic music to suit the libretto: "stromentato" recitative is also used for extra dramatic effect, and the arias are sometimes interrupted by bursts of recitative.  Stylistically, the work is thought to anticipate Italian opera of the following decade, and in particular Mozart's "Il re pastore".

The Cambridge Guide to English Usage: The Cambridge Guide to English Usage by Pam Peters is a usage dictionary, giving an up-to-date account of the debatable issues of English usage and written style.  It is based on extensive, up-to-date corpus data rather than on the author’s personal intuition or prejudice, and differentiates among US, UK, Canadian and Australian usages.  British lexicographer Sidney Landau remarked:

Merenhouse: Meren(gue)house/Merenrap is a hip hop music style formed by blending Dominican merengue music with rap, dancehall reggae and hip hop.  The group Proyecto Uno pioneered the genre.  Merenhouse usually combines a rap style of singing (talk-singing) with actual singing.  It has instruments that are typically in merengue music, such as saxophones, trumpets, accordion, bass, guitar, güira, tambora (drum).  However, they can be combined with electronic sounds or even electronic sounds sampled from the actual instruments (musch like house music).  Sampling music means to take a sample or portion of a sound recording to reuse it in a song.  Merenhouse is very upbeat for dancing, like house music.  It is hard to identify merenhouse based on its time signature and rhythm alone.  Some merenhouse music is in a fast 2/4 beat and has typical merengue style rhythms.  Some also is in a slower 4/4 beat, identifying more with the hip hop style.  Merenhouse can be characterized mostly by the instruments/electronics used and the combination of vocal styles.

Social problem film: A social problem film is a narrative film that integrates a larger social conflict into the individual conflict between its characters.  Like many film genres, the exact definition is often in the eye of the beholder, but Hollywood did produce and market a number of topical films in the 1930s and by the 1940s, the term "social problem" or "message" film was conventional in its usage among the film industry and the public.  Many characteristics that have grown to define the social problem film revolve around the perceived consciousness of the nation about a certain social issue and integrating that issue into a narrative structure.  Social problems such as the horrors of war, suffering of the poor, addiction, the rights of women, and the inhumanity of a certain world are often put on display.  The problem with defining this type of film as a genre lies within the ability it has to separate itself from films that display similar style, as a lot of films do address social issues.  However, the social problem film differentiates itself by focusing on the problems within the historical context of the current time, dealing with the social issue of a certain era as it applies to that era with a style that is much more didactic than its contemporaries.  Furthermore, the social problem film allows further immersion into a certain issue than other genre films.  For instance, gangster and prison films will reflect certain features of a social issue but won't actually fully explore the problem in the way that would qualify it for this genre.

Canadian folk music: Canadian folk music has a long history, dating from the 16th and 17th century, mostly derived from the music of early settlers; much earlier for the music of indigenous people.  Folk music thus differentiates between traditional and contemporary.  Many of Canada's most influential folk artists emerged in the contemporary folk music era, notably Bruce Cockburn, Buffy Sainte-Marie, Ferron, Gordon Lightfoot, Joni Mitchell, Kate & Anna McGarrigle, Leonard Cohen, Murray McLauchlan, Stan Rogers, Valdy, Penny Lang and Wade Hemsworth.  In the 1970s, chansonniers grew steadily less popular with the encroachment of popular rock bands and other artists, and many of the folk clubs, such as the Montreal Folk Workshop, and groups such as The Raftsmen, the Mountain City Four and, eventually, The Travellers, that had served to foster the mid-20th century revival closed down.  Some new performers did emerge, however, including Jacques Michel, Claude Dubois, and Robert Charlebois.  The Canadian Folk Music Awards are presented annually to musicians carrying on in the tradition.

Sertanejo universitário: Sertanejo Universitario is a brazilian musical style that comes from a mix of Sertanejo, segments of freestyle, and funk carioca with touches of beats coming from Arrocha.  It is considered the third segment in the evolution of sertaneja music, coming after sertanejo roots and romantic sertanejo, very popular between the decades of the 1980s and 1990s.  Simple songs dominate the style, and those sung by two singers of the genre, who are overwhelmingly young and considered "College Kids."  (Universitario).  Instead of traditional accordions and violins, synthesizers and electric guitars started to be used more frequently in this style of music.  This variation differentiates itself from sertanejo as it has more elements of pop, and informal language.

Supporting paragraphs: Arioso Recitative
Answer: It resembles sung ordinary speech more than a formal musical composition.