Gunshots as musical overture has been a convention of rap since NWA established gangsta with 1988's Straight Outta Compton. On that album, the impact of machine-gun patter opening a track was twofold: the rhythm suggested the genre's beat-heavy aesthetic, while the song structure literally and figuratively mirrored its message. That is, gunshots both established a track's narrative trajectory -- appearing musically at the very moment that shots were fired in the "plot" -- and indicated violence by and against the black community as the dominant thematic concern.

As the implied politics of rap were distilled into increasingly specific subgenres, with Arrested Development and Digable Planets leading the way, African American music as social reform acquired a unique power - roughly what advertisers describe as direct, not to mention directed, marketing. But it wasn't until this February that the political impact of rap was fully realized as overt protest music. It wasn't until the year 2000 that specific, newsworthy gunshots replaced NWA's fictional ones as the impetus for songwriting, providing rap's first legitimate "Ohio" and refracting early gangsta as perversely prophetic.

Following the acquittal of the police officers who killed West African immigrant Amadou Diallo - as he sought his wallet to show them identification - Mos Def and Talib Kweli of Black Star reached out to the hip hop community to address police brutality. The result was the Hip Hop For Respect project, a musical protest including RZA, Pras, Phaorahe Monch, Shabaam Sahdeeq, Rah Digga, Capadonna and other prominent rappers.