Children's pop in bright mid-tempo 4/4 with handclaps, playful synth bells, bouncy acoustic guitar, and a simple marching drum pulse; verse stays light and conversational, pre-chorus lifts with stacked child vocals, chorus opens wide with group singalong repeats and birthday shouts. Lead vocal is warm and close, with claps, little echo tails, and a few joyful gang ad-libs. Crisp, colorful mix with glossy top end and a festive, candy-like feel.