When Kelly Clarkson opened her mouth and sang, as she did often during the run of ''American Idol,'' the evolution of pop vocalizing over the last decade poured out with her words. She would begin with a whisper, but she wouldn't remain that way; within moments, she would rev up to a full-throttle belt. Her goal wasn't to explore the nuances and emotions of a lyric but to tackle it and beat it into submission. (By the show's finale, she had morphed into the music-biz equivalent of Reese Witherspoon's steely, careerist character in ''Election.'')
The most frightening aspect of American Idol wasn't the showy way its star wannabes covered pop oldies but the realization that this type of florid vocal-sandblast approach now defines quality for an entire generation. For that, we can blame the likes of Celine, Whitney, and Mariah, whose collective influence is glaringly apparent throughout Clarkson's single: studio recordings of the song that capped her victory, Before Your Love, and the one her producers chose for her post-victory performance, A Moment Like This. On record, Clarkson emerges as a diluted version of those divas. She doesn't yet have their lung power or vocal tics, but she makes it clear she's on her way, from her breathy curlicues to the hint of a growl you know damn well will blossom on her eventual album.
As vehicles for this style of balladeering, the songs are drearily appropriate. The lyrics are generalized banalities (''I never lived before your love/I never felt before your touch''), the melodies destined to endure as wedding songs or florist ads. A choir at the end of ''A Moment Like This'' is meant to indicate earthiness; the gentle acoustic guitar throughout ''Before Your Love,'' sensitivity. Neither gimmick lends the songs heft: A buttery tune is one thing, but these melt into ooze as you listen to them. When Clarkson hits the climactic line in ''A Moment Like This'' -- ''I can't believe it's happening to me'' -- the performance is transformed. Instead of a love song to a man, it becomes a tribute to ''American Idol'' and to Clarkson's conquest; it's an infomercial with orchestra. Like the series itself, the song is smitten with instant fame and all-conquering commercial success, and it's not at all embarrassed to blare its infatuation to the world.