Before "Walk This Way," there was "Rock Box." History may possibly emphasize the former, but Run-D.M.C.’s groundbreaking of rap-rock begins with the duo rapping over the sweet guitar sounds of Eddie Martinez. Much like Outkast’s "B.O.B.," "Trill" is the audio of a rap duo shifting beyond the parameters of its seem and asking absolutely everyone else in the rap match to keep up.