The career of Guarionex Castro is the story of the mambo era's front-line voices: he was at the front of Rikarena when Kinito Méndez's project brought merengue mambo to dominance in the mid-1990s, and went on to co-found Klibre with two of his bandmates from that run, the group he still fronts today. One correction belongs at the front of his catalog file: the printed credits of his records document him as a lead vocalist, not as a güira player or an arranger.

Rikarena's founding front line

Rikarena was Kinito Méndez's laboratory — a young, fast, choreographed mambo machine built around a four-man vocal front. On the debut album, «¡Sacúdelo Que Tiene Arena!» (J&N Records, 1994), the printed credits list Guarionex Castro under Lead Vocals and Backing Vocals, alongside Henry Trinidad, Shiro Méndez and Wester Hernández. Dominican memory attaches his voice to that first explosion — the audit of merengue singers calls him the “voz original de Rikarena” and names «Merengue Riko» and «Cutibiri Pachá» as his signatures, and footage of the group performing «El Merengue Riko» on Sábado de Corporán in 1994 shows that front line at work. His documented span with the group covers its first three productions — the debut, «Mas Rika Que Nunca» (1995) and «Sin Medir Distancia...» (1997) — the same years in which Víctor Manuel de la Cruz, Beko, directed the music.

Klibre

When the first Rikarena cycle closed, three of its men started over together. Castro, Wester Hernández and Beko co-founded Klibre — written K-Libre, and «Kalibre» in Listín's pages — and the new group recorded at the same mambo tempo: «Mambo Con...» (Musical Productions, 1998) and «¡Con Mucho K-riiiiño!» (1999), followed by a run of compilation appearances into 2002. The audit dates the founding to 2000 while the catalog opens in 1998; the discrepancy stands in the record unresolved. What is not in doubt is the continuity: in July 2026, on Klibre's official Facebook page, Castro introduced himself on camera — “les habla Guarionex del grupo K-libre, ex integrante de Rikarena” — announcing a fiestas-patronales date. Three decades after the debut, the voice is still the front of the band.

Legacy

Castro's legacy is a front-line voice in two acts of the mambo era: the founding Rikarena, whose first records set the template for a generation of mambo groups, and Klibre, the alumni band that carried the same singers into a second career. He never became the name above the title — Kinito Méndez owned that — but «Merengue Riko» was sung first in his voice, and the mambo generation remembers it that way.