Remus did not mind being unfamiliar with the music and newer things, as long as Tonks didn't grow impatient or bored with him. As long as she had a good time, he was happy. He'd figure out how to dance to this music by watching other people first to see what was the norm.
"Let's get a drink first?" he suggested, leading her gently to the bar. He wanted to sit and observe first. Once they sat down, he exchanged pleasantries with the bartender and ordered a gin and tonic for himself.