Richard Thompson knows that a family that plays together isn't always one that stays together. Yet Thompson nevertheless made his current tour a take-your-son-to-work affair. The presence of rhythm guitarist and backup vocalist Teddy Thompson, a 23-year-old product of Richard and his ex-band-mate and wife Linda Thompson, added a touch of soap opera to the otherwise typically dazzling show put on by his dad at the Birchmere on Sunday.

His parents, of course, also produced a series of five-star albums in the late 1970s and early 1980s, all laden with devastating portraits of a relationship heading toward disintegration. In his current role, Teddy must chant Linda's old lines--though in lower keys than those favored by his mum--as well as some caustic couplets Dad wrote about her after the Thompsons' band and marriage broke up. The irony was particularly heavy-handed during "A Heart Needs a Home," from 1974's "Hokey Pokey," and the brutal post-parting shot from 1985, "She Twists the Knife Again."

Most of the material on Richard Thompson's newest CD, "Mock Tudor," deals with less fiery romantic entanglements. He described "Walking the Long Miles Home" as a song about breaking up on a public bus.

Lest the show be weighted down by all the tales of domestic dysfunction, Thompson reprised "1952 Vince Black Lightning," a love song about a two-bit outlaw and his bike. And his harmonics-heavy, overdriven guitar solos during "Tear-Stained Letter" left everybody in awe. From across the crowded stage, Teddy stared at the fretboard of Dad's instrument with a look of mystery on his face. Apparently he couldn't figure out where all those sounds were coming from, either.