This study seeks to document and preserve the Dinagjang Beat of the Ati Tribe in Calvario, Loay, Bohol, through rhythmic notation and analysis of its musical structure. The Dinagjang Beat, performed during rituals and festive gatherings, serves as an essential expression of the Ati community’s devotion to the Santo Niño and as a marker of their cultural identity. Despite its cultural importance, scholarly documentation of the beat remains scarce, particularly in terms of rhythmic structure, tempo, and instrumental interplay. Addressing this gap ensures the preservation of an indigenous musical tradition that has long been transmitted orally. A descriptive-qualitative design was employed, combining participant observation, interviews with Ati musicians and culture bearers, and rhythmic transcription using standard notation techniques. Data analysis followed Aquino’s (1976) approach to rhythmic notation and Sinaga’s (2019) Music Composition Process, enabling a systematic interpretation of the rhythm. Findings reveal that the Dinagjang Beat is characterized by a 2/4 meter, Allegro tempo, and percussive layering of bass drum, two-headed improvised drums, and kalatong. Each instrument contributes distinct rhythmic patterns, with the bass drum providing the pulse and the improvised drums and kalatong supplying syncopation and textural variety. By documenting and analyzing the Dinagjang Beat through rhythmic notation, this study contributes to Philippine ethnomusicology, cultural preservation, and education. The results not only safeguard an intangible cultural heritage but also provide a valuable resource for future comparative studies, music pedagogy, and efforts to integrate indigenous sounds into contemporary performance and scholarship.