Soak corn in cool water 15 minutes. Pull back husks; remove and discard silks. Drain corn, and pat dry.
Stir together butter and remaining 3 ingredients; brush onto each ear. Pull husks back over corn. Tie string around husks, if desired.
Grill, covered with grill lid, over high heat (400° to 500°) 8 to 10 minutes on each side. (Watch carefully to make sure husks do not catch fire.)
Note: Corn may be husked and wrapped in foil. Grill, covered with grill lid, over high heat 30 minutes, turning every 10 minutes.