He originally played the standard pre-war repertory of Texas border music -- waltzes, huapangos and schottisches -- but then began to add new elements. He learned the Colombian cumbia while living among Puerto Ricans in Chicago in the late 1950's, and after he adopted it, it became an important part of Mexican-American conjunto. He popularized, if not pioneered, the practice among south Texas conjunto musicians of playing the accordion while standing up and it is said that he was the first to use the modern trap drum set in conjunto, in 1948.

Longoria created a different style of playing, improving on that of Martinez -- ''a smoother style, with longer extended runs,'' said Juan Tejeda, a conjunto music historian. He also sang while playing the lead line on the accordion, another innovation.
Conjunto is a hard-driving dance music in which the accordion leads a small band that also includes the guitarlike bajo sexto and the drums. In the development of the music, Mr. Longoria was the next major innovator after creators of the form like Narciso Martinez and Santiago Jimenez.

Longoria was born in Clarksdale, Miss., in 1924, one of nine children of cotton field workers, and spent his early childhood in Kennedy, Tex. He began playing accordion at age 7, and he was soon under the spell of Martinez, the accordionist who in the mid-1930's helped conjunto become a popular, working-class dance music and created a new, more indigenously Texas-Mexican style of playing the accordion, with fewer bass notes and more focus on the melody