Stepping into this Motown-era seafood palace — advertised by one of Oakland’s truly great neon signs — is like time traveling to another era. Which is not altogether surprising since Art’s has been slinging buckets of garlic-butter crab since 1963. Except for the contemporary prices, Art’s feels like the ’70s preserved in amber: beer signs, faux ferns, booths in a row opposite a well-used bar. They might as well be playing the theme from Shaft on the jukebox. It’s a dark, windowless cavern halved by restaurant and bar sides, and, curiously, customers must pay in advance. It helps to know the drill, which is namely to order what you think you might want on the front end, including beer; otherwise service may seem slow or a little spotty. But it’s easy to forgive these incidentals when the buckets of herb-rich, still-in-the-shell, easy-to-crack crab arrives swimming in a sea of butter, garlic, and mushrooms. It’s a gluttonous, messy undertaking that requires quite the clean up, but for shellfish this good, it’s worth it. Here’s a tip for first-timers: Use the bread to sop up the juice.