At the turn of the last century, to have one’s portrait painted by John Singer Sargent was to say that you had arrived. And now a new exhibition at the Tate has arrived, from Boston, celebrating his work alongside fabulous costumes contemporary to this era. Wealthy and successful individuals chose Singer-Sargent to portray them as they wished to be seen; self assured, attractive, and elegant . They often came from ‘new’ money, the wives and children of businessmen…