Hard is a word that wields a lot of power in hip-hop. Often, it’s treated like a unit of measurement for abstract ideas like street cred or masculinity. But when it comes to beats, there’s just no other word for it: drums that punch you in the face or horns that feel like they’re blaring right in your ear—shit that simply sounds hard. Some of hip-hop’s best beats sway or creep or groove, but tracks are never quite as satisfying as when they sound like a giant brick wall of percussion. Some of them forced their way into mass consciousness, while others were simply too tough for the radio, but these are The 25 Hardest Rap Beats of All Time.