Disco with a driving four-on-the-floor pulse, bright slap bass, clipped rhythm guitar, and shimmering string stabs; verse rides a playful groove with light percussion and handclaps, pre-chorus lifts with rising synth sweeps and stacked harmonies, chorus hits wide with gang vocals on the name. Lead vocal is upbeat and close-mic in verses, doubled and ad-libbed in hooks, with short delay throws on the birthday name. Ear candy: vinyl crackle into the intro, reversed disco swells before choruses, glittery bell accents between lines. Mix is glossy, punchy, and dancefloor-bright.