As an undergraduate, Joanne Leonhardth Cassulo had taken just one art-history course. So when the young Texan decided to get a master’s degree in fine arts at Southern Methodist University, even she wasn’t precisely sure why. Nonetheless, the hunch turned out to be an inspired one. After firing through with a 4.0, she won a Helena Rubinstein Fellowship to the Whitney, where she specialized in mueseum studies-basic training for future curators. She soon knew what she wanted to do and where she wanted to do it.