If the pairing of singer/songwriter Teddy Thompson and Canadian Lilith fairies Tegan and Sara a week ago Tuesday was any indication, then Neil Young's endorsement carries a bit more weight than Richard Thompson's bloodline. Tegan and Sara, a short and spiky-haired Canadian duo who sported a pair of acoustic guitars and earlier this year released their debut CD on Neil Young's Vapor label before hitting the road with him, were the opening act. Nevertheless, they drew the larger crowd at T.T. the Bear's Place for a show headlined by Thompson, the twentysomething son of Richard and Linda Thompson.

On stage, Thompson and Tegan and Sara seemed two sides of the same folk-pop coin. Like Tegan and Sara, who are still young enough to be telling high-school stories, Thompson, who was joined by a second guitarist, sang sensitive, sometimes soulful songs from the heart accompanied only by acoustic and the occasional vocal harmony. Although somewhat more reserved than the gregarious Tegan and Sara, he too took time out to introduce several of his songs. To find major differences other than gender between the two acts, you have to refer to their respective debut albums. Tegan and Sara's -- This Business of Art -- is a hip-hopped-up pomo-pop production that sounds like a cross between Luscious Jackson or a less adventurous Beck and the Indigo Girls -- which goes a long way toward explaining their draw. Thompson's, on the other hand, is the kind of straight, polished, singer-songwriterly offering that there's barely a radio format for these days. Indeed, though Teddy's quite a bit handsomer than his dad and not nearly so dour, Teddy Thompson (Virgin), with its solid bass/drums/guitar arrangements, isn't all that different from the kind of commercially marginal albums his father makes. It even features Richard's guitar on several cuts (as well as background vocals by Loudon Wainwright III's son Rufus Wainwright, who gets a co-writing credit on one song).

Live, Tegan and Sara's less developed material suffered the most for the lack of more dynamic backing, though Sara's amusing between-song banter kept the set interesting. Thompson, whose nearly whispered comments were all but indecipherable, writes songs that lend themselves well to stripped-down settings. Still, it'd be nicer to hear him with a drummer, a bassist, and, oh, maybe his dad playing guitar. That might just improve his draw as well.