If you want the best people-watching seats, take up residence at one of the booths and banquettes surrounding the dance floor and opt for premium bottle service or tableside mixology.
Local peoplewatching is at its best at Mercado Central de San Pedro in Cusco, where fruits and vegetables are sold alongside laundry detergent and pet food.
Apart from my classical training in piano, I have learned everything I know about music by watching other people -- many of them the best in their fields -- play online.