They soldier on, making their sweet piercing music, enjoying decent careers and, every couple of years, releasing a CD that enriches the pop-music vocabulary. Mary Chapin Carpenter and Shawn Colvin are close to the best there is in today's bounty of singer-songwriters. But hovering above them, like a gargantuan nightmare kid sister, is the brutal fact of Alanis Morissette, whose primal whining has moved 15 million copies of her first album. It must be a perplexity for Carpenter, whose songs have cannier pop hooks, and for Colvin, whose angst-filled anthems predated and surpassed Morissette's--though she's too polite to scream them.
On...