This article explores Auto-Tune's importance to the production, perception and reception of trap music, a sub-genre of hip hop. Central to this exploration is the observation that Auto-Tuned trap vocals are readily audible as such because the software's pitch correction function is applied unnaturally quickly to the vocal audio signal, a feature herein termed ‘zero-onset Auto-Tune’. First, I posit that although Auto-Tune is ostensibly a pitch-correction device, its impact on vocal timbre is not well documented or understood. Second, I argue that Auto-Tune's recent importance as a creative tool in trap recasts it as an instrument. Third, I suggest that understanding Auto-Tune's repurposing as an instrument begets its situation in a lineage of technologies repurposed, adapted and embraced by the hip-hop community, including the turntable, digital sampler, and analogue mixer. And fourth, I propose that this repurposing surfaces in Auto-Tune's ability to facilitate emotiveness in trap vocals.