The Texas-Mexican conjunto, a genre of música norteña, has evolved since the turn of the century as an important musical form developed by Texas-Mexican working-class musicians, who adopted the accordion—the main instrument in conjunto music—and the polka from nineteenth-century German settlers in northern Mexico.
The conjunto grew out of the cultural links between Texas and northern Mexico at the end of the nineteenth century, when inexpensive one-row accordions became readily available. Tejano musicians took up the accordion as a solo instrument and used it at rural social events such as the fandango, a combination of dancing, eating, gambling, and other merriment, which remained a part of Tejano working-class life to the end of the nineteenth century. In the late 1890s the musicians began to pair the accordion with the tambora de rancho (a homemade goatskin drum) and later the bajo sexto (translating as "sixth bass"—an acoustic twelve-string version of a bass guitar).
Narciso Martínez has been called the "father" of the modern conjunto for promoting the accordion and the bajo sexto and for his unparalleled creativity as an accordionist. Martínez, also known as "El Huracán del valle" ("The Hurricane of the Valley") for his musical virtuosity, became a wizard of the two-row accordion in the 1930s. Santiago Jiménez, Sr., of San Antonio was another outstanding accordionist of this formative period. He contributed one innovation to the conjunto by adding a tololoche (contrabass), which, however, did not become a standard feature of the ensemble until the 1940s and was replaced with the electric bass in the late 1950s. Valerio Longoria, one of the foremost conjunto musicians of the 1940s and 1950s, combined his vocal talent with his accordion playing, and his repertoire increased interest in accordion-accompanied singing. Tejana singers also came to the fore in the 1930s with Lydia Mendoza. Female duets, which were popular by the early 1950s, were often accompanied by the increasingly popular accordion. One record featured Martínez on accordion with Mendoza and the famous Tejana duet Carmen y Laura as vocalists.
The vocals Longoria incorporated were called canciones rancheras ("ranch songs"). They became standard features of the conjunto. Rancheras are still sung in the slow (waltz) or fast (polka) tempo. Longoria shaped the modern conjunto in several other ways. He added the bolero, previously considered a part of "genteel" music because of its regal pace. This addition resulted in more intricate singing because vocalists in the bolero were required to use harmony and rhythm with more acumen. Also, the conjunto audience's acceptance of the bolero signified growing musical sophistication. Longoria altered the accordion's reeds to give it a distinctive sonido ronco ("hoarse sound") and was the first to use drums in the ensemble, a change considered the most "radical innovation" in conjunto music. With these alterations, as well as the addition of amplification, the modern conjunto was established as a four-instrument band: accordion, bajo sexto, electric bass, and drums.
Since the 1960s the Texas-Mexican conjunto has grown in prominence among Hispanics throughout the state, particularly in San Antonio, Austin, Alice, and Corpus Christi. Conjuntos headed by Paulino Bernal, Roberto Pulido, Ruben Vela, and Leonardo (Flaco) Jiménez gained stature during this era. A few innovations have occurred. Paulino Bernal and Esteban Jordan imbued their conjuntos with their unique personal styles. Bernal augmented his group's sound by including three-part vocals, and Jordan, who criticized conjuntos for their rigid attachment to the traditional polka approach, blended other musical forms, including jazz, into his playing style. By 1990 he was considered the leading individual experimenter in the new conjunto sound. Other groups, such as Inocencia and Emilio Navaira and Rio, took Jordan's vision to heart and added saxophones, keyboards, and synthesizers to their sound. Their resulting music, called conjuntos orquestal, gained popularity and has been performed in the important annual Tejano Conjunto Festival in San Antonio.
In the 1990s the Texas-Mexican conjunto drew even more general interest. Flaco Jiménez, the son of Santiago Jiménez, played in Europe. He also added the conjunto beat to other popular music by teaming up with other musicians, including the Texas Tornados. Their "Soy de San Luis" received a Grammy in 1991. Conjunto, despite its Spanish lyrics, thus found new audiences. The conjunto's distinctively rousing delivery of its trademark música alegre ("happy music") has seemingly transcended ethnic and language barriers. The annual Tejano Conjunto Festival in San Antonio and the Conjunto Music Hall of Fame, along with the Tejano R.O.O.T.S. Hall of Fame Museum in Alice, as well as the Texas Conjunto Music Hall of Fame and Museum in San Benito, have also increased its prestige.
Since 1982 the Conjunto Music Hall of Fame has recognized the achievements of more than sixty conjunto musicians or promoters, including Narciso Martínez, Tony de la Rosa, and Juan Viesca. In 1991 it inducted Lydia Mendoza. Although the role of women in conjuntos has been mostly limited to singing, accordionists Eva Ybarra and Lupita Rodela garnered critical and public recognition, and Tejanas have achieved growing prominence in the early twenty-first century. Grupo Imagen from Corpus Christi, for example, formed in 2013 and was heralded as the first all-female conjunto band. They took part with other Tejanas as performers in the “Women in Conjunto Music Tardeada Showcase” at the 2015 Tejano Conjunto Festival.
Many major conjunto musicians have worked alongside their audience as fieldworkers or common laborers, composing and playing music in their free time, often for meager compensation. Música alegre brought cheer. Some made their careers playing the "taco circuit," the public dances organized along the roads that Texas-Mexican cottonpickers followed to the harvests. Although individuals propelled conjunto music to new stages, the conjunto phenomenon emerged from a "collective folk" tradition to which many individuals contributed. By the end of the twentieth century the Texas-Mexican conjunto had emerged as a distinct musical form that, like the corrido and orquesta, was the product of a few acclaimed and countless uncelebrated border musicians. With the 2001 publication of ¡Puro Conjunto! An Album in Words and Pictures, the contributions of the Texas-Mexican conjunto to the music and culture of the Lone Star State received long overdue attention by major scholars and writers.