What songs can I sing as a singer in a five-star hotel?

It depends on what kind of pub it is! If it is rock, then there must be more rock singers and more natural rock singers. If it is jazz, it is usually jazz. If it's a blues pub, there must be some very emotional mix musicians. Others and so on ... In short, each pub has its own style, and naturally, the singers and musicians in it will also have different styles. Choosing what you like is king.