Art: TASTEMAKERS' CHOICE

IN the last weeks of spring museum men descend in droves on Manhattan to tour the galleries, see what their colleagues are buying and pick up the latest gossip before the summer doldrums set in. To help them out, Manhattan galleries this week are busy staging their own "season survey" and "new discoveries" shows. In addition, the Modern Museum is showing its "Twelve Americans" of the year,* and two galleries are displaying the current choices and future bets of 19 museum directors and curators. The whole lavish display points up a new trend in the market place of modern art: since...