Isidro Castillo Flores, known as Isidoro Flores, was born in 1912 in the Pajarito section of the Quisqueya sugar mill in San Pedro de Macorís and died in Puerto Rico on 7 January 1973 — a leading accordionist of the eastern Dominican merengue típico tradition, a distinct regional sound from the better-known Cibao style.

From the cane fields to «La Voz del Yuna»

He learned accordion watching his father run a business that hosted country dances, and formed his first group at the Las Pajas sugar mill in the 1920s, playing for cane cutters. A move to Hato Mayor in search of opportunity led an army recruiter, Pedrito Trujillo, to spot his talent, and that connection opened the door to twenty-three years hosting a traditional música típica program on La Voz del Yuna, today CERTV.

«Cuarteto Flores»

He led his own group, Cuarteto Flores, with Tavito Peguero, Neftalí Castro and Juan Cabrera, sometimes joined by the singers Thelma and Celeste Cruz, recording five LPs. Of the more than a hundred pieces he composed — mostly merengues, mangulinas and salves — «Carmela Linda», «Fiesta en la Joya» and «El Gallito Pinto» remain among his best known, alongside the salves «Blanca Flor» and «Salve de la Aurora».

Radio, stage, and a dispute over authorship

His ensemble supplied the music for «La Hacienda por la Radio», a daily program aimed at rural listeners, and he appeared himself, playing a Haitian character, in the folk comedy duo Felipa y Macario, for whom his tune «Heroína» served as a theme song for decades. He publicly defended his authorship of «Fiesta en la Joya» after the Puerto Plata composer Félix López claimed the song as his own.

Exile and an unfinished return

In 1968, unable to make a living from his music at home, he emigrated to Puerto Rico, where the following year he formed a new ensemble, Los Alegres Dominicanos. He had everything ready to move back to the Dominican Republic for good when, the night before his planned return, he collapsed while playing accordion at a house party in Puerto Rico and died shortly after at a hospital in Río Piedras.

Legacy

Two of his nine children carried the music forward — Domingo Flores as an accordionist like his father, and Isidoro «Ply» Flores Jr. as a singer — and Isidoro Flores himself is remembered as one of the most authoritative voices of Dominican folk music, and of a merengue típico sound the Cibao never fully claimed as its own.