Flipsyde

Flipsyde are an American rap rock group from Oakland, California, that fused hip-hop vocals with live-band instrumentation and rock and soul textures, part of a wave of genre-blending acts in the mid-2000s. The group reached international attention with «Happy Birthday», a song built around a rap verse and a hook that interpolates the piano and vocal melody of t.A.T.u.'s «Gomenasai», giving the track a melancholic, anthemic quality distinct from typical rap-rock bravado.

The group's sound paired socially conscious, sometimes autobiographical lyricism with hooks aimed at radio and pop audiences, a combination that made «Happy Birthday» a crossover hit in multiple countries even as the group's presence in the US mainstream remained comparatively modest. Their material touched on street life, struggle, and resilience, filtered through a more melodic and rock-inflected production style than much of contemporaneous West Coast hip-hop.

While Flipsyde never became a fixture of the American charts on the scale of their European success, «Happy Birthday» remains their signature and most enduring work, an example of the 2000s trend toward hybrid rap-rock singles built on unexpected samples and emotionally direct hooks.