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Although she's worked with everyone from Jay-Z to Nas to 50 Cent, it's safe to say you don't show up to an Alicia Keys concert expecting an appearance from one of hip hop's most vitriolic MCs. But the lucky crowd at the R&B singer's Madison Square Garden concert received that rare, incongruous treat when DMX joined Keys onstage Thursday night.

Swizz Beatz—Keys' husband and the producer of approximately a million DMX tracks—came out, too, which meant the unsuspecting audience was privy to a Ruff Ryders mini reunion. DMX hit the crowd with his first Top 10 single "Party Up" and the It's Dark and Hell Is Hot classic "Ruff Ryders Anthem."

DMX did not, however, perform his indelible take on the Reading Rainbow theme. Oh well! There's always next time. Until then, watch this tragically short YouTube clip from the MSG show below.