The Assembly Theaters on Broadway in New York City.
The first of these concert saloons, the Melodeon, opened in 1859 and was quickly replicated by hundreds of others. Tended by show-stopping “waiter girls,” these theaters gave patrons a place to relax, drink and dance, and set a standard for entertaining that continues to be emulated by modern cocktail lounges, bars, and clubs. They offered piano men and lewd theater, talented dancers and drunken musicians, and more than a few waiter girls who, for some extra cash, might be amenable to discreetly joining you in a curtained alcove.
The saloons along the Bowery were down and dirty; the ones on West Houston were the places to see and be seen. They turned Manhattan Island into the city we know.