Mary's Underground is a restaurant and jazz bar in the space formerly occupied by live music venue The Basement, which entertained Sydney for 45 years. On the surface, Mary’s serving lobster and steak frites in a jazz club may seem jarring. The reputation preceding it doesn’t exactly scream “fancy” – burgers, fries and fried chicken would be considered more its remit. But look just a tiny bit below the superficial and you’ll see that this thoughtful streak has been there all along, in everything from the top-notch ingredients Mary’s uses in its popular burgers to the natural wine it helped pioneer in Sydney. Everything at Mary's Underground makes a weird kind of sense. Whereas upstairs at Mary’s Circular Quay the waitstaff blares ’90s music and serves burgers. Downstairs, at Underground, it’s a different story. There’s lobster on the menu, served classically and without a hint of irony. There’s dry-aged duck from a special dry-ageing room, where they get the skin nice and dry for complexity of flavour. Co-owner Jake Smyth's long-standing suppliers source him everything from the aforementioned duck to little purple potatoes from Tasmania, which are turned into a salad. The focus is on classic flavours, served thoughtfully and sourced carefully. It might seem like a change of tack from the notoriously over-the-top Mary's gang, but considering Smyth and co-owner Kenny Graham both have backgrounds in restaurant-style dining, this is more of a return to the beginning than a brand new one. The wine list leans Australian, natural and organic, and its poured by well-respected Sydney sommelier Charles Leong and chosen by Mary's wine director Caitlyn Ress, who used to run the wine show at Fred’s. When the Mary’s guys took over The Lansdowne pub in Chippendale, they enlisted booker Josef Muller to be its head of music. He’s behind the program at Mary’s Underground, which leans heavily on jazz but in a more updated mode than people came to expect from The Basement. They’ve even booked a house band. The band leader presides over a five-piece of New Orleans-style brass and drums players. They play every Friday night. Some bands will play one night a week for a few months, others for just a couple of weeks. The stage here has hosted names such as Herbie Hancock and Prince. Every week young musicians from around Sydney are invited to put their hands up and play a gig. The vibe can lurch wildly from smooth and restrained to full-blown party. It's a mixed bag, but it's always fun.