Wolf Trap presented a potent double bill last night. First there was a torrential rain, bringing welcome relief to bodies soaked with sun. And then there was Judy Collins, whose shimmering voice soothed minds worn thin from dealing with summer in Washington.

The word "haunting" does not really do justice to Collins' singing. Her voice is an ethereal crystalline presence which drifts through the hall, only to disappear in the darkness. Coming as it was at times last night from a dark stage and accented with distant flashes of lightening, the voice became a thing of eerie beauty.

Collins, a performer who has been around for two decades, is one of few artists to make a successful transition from straight folk to well-rounded pop singing. Her show featured a wide range of songs from composers as diverse as Ned Rorem, Jacques Brel and Stephen Sondheim, as well as several selections of her own. There were many high points, including her renditions of "Both Sides Now," and the title song of her new record, "Running for My Life," but her quietly dramatic reading of "Send in the Clowns" was a moment to be stored away and savored at less-affecting musical shows.

Judy Collins did an admirable job of brightening up a miserable day and possibly the rest of the season.