The hospitality group behind Loulou Bistro and The Charles Grand Brasserie have made their first foray into Sydney's late-night music scene with the opening of Tiva, a subterranean lounge bar on King Street.

With Tiva, Etymon Project has taken its characteristic brand of French glamour to the next level: There are tableside cocktails, an extensive list of champagnes by the glass and a caviar service starting from $140.

The snack menu is similarly indulgent, featuring steak tartare crumpets ($18), hash browns with roasted chicken cream ($15) and shaved wagyu sirloin with black garlic ($42).

Director of bars Jonothan Carr describes the vibe as "sophisticated, luxe and moody".

"[It's] a place you want to settle in to enjoy the music," he says.

"High-end spirits, elegant cocktails, champagne and table service with some understated theatre are the ultimate support act to the incredible entertainment planned."

A diverse mix of live music will be on offer from Wednesday through to Saturday, curated by Dan Lywood of music consultancy Playlister FM (Chateau Marmont).

"Expect the cream of the country's players and international guests presenting live music four nights a week, alongside a diverse and exciting roster of established and up-and-coming DJ talent," Lywood says.

The interiors, designed by H&E Architects in collaboration with COX Architecture, are softly lit and "ethereal", featuring deep velvet lounges, gold furnishings and blackened steel detailing.

We asked Carr for his tips on how to get the most out of a night out at Tiva.

What's your pick of the drinks' list?

Choosing just one is tough. A personal favourite is the tequila rose ($26), a martini made with Altos Reposado Tequila, Lillet Rose Vermouth and violette liqueur. It's a great extension of the venue vibe and, well, shaken tequila martinis are delicious.

The Tiva Old Fashioned For Two ($160) is a showstopper. We use the best spirits: Hennessy Cognac, Glenmorangie Single Malt, Sazerac Rye – and then serve it in a stunning three-piece glass decanter which we dissemble and pour tableside.

Tiva has around 65 different champagnes available and so the Champagne Cocktail ($30) made with Moet & Chandon, Anejo Tequila and aromatic bitters is a nice complement to that.

And finally, our Godfather Sour ($26) fits in so perfectly in this venue – amaretto, Chivas, the Italian bitter aperitif Cynar and citrus.

What's your must-order snack?

The menu is largely designed as snacks you can pick up in one hand – ideal cocktail and champagne accompaniments. Earlier in the night, I'd go for something like the spanner crab with creme fraiche and trout roe ($15) and then later, the hash browns with roasted chicken cream ($15).

Best seat in the house?

Depends what mood you're in. If you're really into the music, get one of the lounges closest to the stage and have that front-row experience. If you're on a date, I'd opt for one of the sexy, dimly lit booths. If you're flying solo, pull up a bar stool and let the bartenders keep you company.

What's the best time to visit?

We've programmed entertainment seven nights a week, so you can visit any night and enjoy great music. There are no hard and fast rules, but Wednesdays are typically jazz, Thursdays are for rhythm and blues, Fridays more soul/funk music, and Saturdays is a surprise – it could be Latin or pop or roots for example. The bands and DJs performing are truly some of the best in their style.

There's something special about live jazz that works so well in this space. Wednesdays are the night I look forward to most, although the eclectic style of bands playing on Saturdays are fun too.

Bookings and walk-ins available

Open daily 4pm-late

Basement, 68 King Street, Sydney