To rehearse for his part as Chopin in the movie Impromptu which costars Judy Davis, Julian Sands, and Mandy Patinkin British actor Hugh Grant took intensive piano lessons with South African maestro Yonty Solomon. It wasn't finger positioning, however, but body language that Grant, 30, found himself learning: ''Solomon had me dancing around the room 'expressing myself,' which really isn't me at all,'' he says. ''Quite embarrassing, what with the maid popping in and out.'' Despite the workout, Grant says he's unable to evaluate his keyboard debut on film. ''I was too busy looking at my wig,'' he says. ''It looked like a 12-year-old girl's wig. We all wore them. When we sat together, it looked like a schoolgirls' outing.''
Grant, who has also appeared in Maurice, Lair of the White Worm, and White Mischief, drops the 'do for his upcoming TV movie, Our Sons, starring Ann- Margret and Julie Andrews. As the lover of a man dying of AIDS, the London native convincingly drops his English accent as well. Grant practiced a ''preppy East Coast'' dialect on cabdrivers, ''until it embarrassed my girlfriend (actress Elizabeth Hurley) so much that I stopped.'' His next movie, Roman Polanski's Bitter Moon, begins filming this August. ''I'm terrified,'' Grant deadpans. ''At least I'm not a 12-year-old girl.''