The shows at the Lizard Lounge last Friday and Saturday that brought together nine performers — two bands and two solo artists — were billed as "Family Affair," but few real families function as smoothly or collaborate as well as these musicians did on stage. Then again, these concerts had been a work-in-progress for years, the result of a slowly evolving web of friendships and musical unions that finally culminated in this basement club in Cambridge.

On stage Saturday night were the nucleus of the Twinemen, Morphine members Dana Colley and Billy Conway plus singer Laurie Sargent, along with singer-songwriter Kris Delmhorst, singer/mandolinist Jimmy Ryan, and three-quarters of Maybe Baby, singer-songwriters Ry Cavanaugh and Jen Kimball plus drummer Billy Beard, joined by bassist Andrew Mazzone and guitarist Kevin Barry. On Friday night another locally based guitar ace, Duke Levine, occupied the six-string seat.

As for the relationships, Beard and Conway, two of the region’s best drummers, have been pals for years. Conway and Sargent have a longstanding romance, and Colley and Conway have Morphine’s decade-plus run in common. They’ve all been friends and worked with scene veterans Ryan, Kimball, and Mazzone over the past two decades. Barry isn’t as deep inside the web of this "family" as some of its other members, but Conway — along with plenty of other musicians — occasionally attends his guitar-sparring gigs with Levine at the Tír na n-Óg in Somerville, and Barry and Levine often play with Maybe Baby. These days, however, Barry may be best known for his fusion of soulful blues-based signatures with cutting-edge sonics in Paula Cole’s band. This is a radical oversimplification of their connections, but add to that a healthy dose of shared respect and admiration all around.

What finally channeled all of this into two nights of performances is the fact that Delmhorst, the Twinemen, Maybe Baby, and Ryan have all made albums at Morphine’s studio, High-n-Dry, that have been released within the past 15 months. Delmhorst celebrated the issue of her Five Stories (Big Bean), which was produced by Conway and features Mazzone, Cavanaugh, Conway, and Kimball, in October 2001. The Twinemen’s self-produced The Twinemen (High-n-Dry) was released last summer. Ryan’s solo debut, Lost Diamond Angel (Ambitious), produced by Conway and featuring Colley, came out in the fall. And Maybe Baby’s debut, What Matters, is finished, pressed, and ready for release.

In the weeks before the show, that cycle was beginning anew. A crisp late-December afternoon found Conway, Colley, Delmhorst, and Delmhorst guest Julie Wolf, who most recently played keyboards with Ani DiFranco, working in low-key fashion on the talented and personable Delmhorst’s next CD. As the light fanned out across the worn industrial floorboards of High-n-Dry, the top of an old factory building just outside Cambridge’s Inman Square, Wolf worked on crafting a melodica melody for one song, tweaking the reverb to get the instrument’s sound right in her headphones, as Conway and Delmhorst offered encouragement and listened.

And more discs are on the way from High-n-Dry’s tape machines. Colley has produced Boston singer-bassist Monique Ortiz for Accurate Records, and a disc for jazz composer Andrew Dimola. And Colley and Conway have been working with two new bands led by Conway’s former bandmates in Treat Her Right: singer/guitarist Dave Champagne’s Heygoods and harmonica player/singer Jim Fitting’s Coots. So the "family" ties continue to deepen.

The sonic glue that held Saturday night’s two-hour performance together was a shared interest in American roots music as the big band the nine players assembled themselves into delivered songs that embraced driving rock, pure country, bluegrass, folk ballads, ersatz sea chanteys, and splashes of psychedelia and sonic experimentalism. The music rarely lagged, but some peaks came right at the start, when Sargent began a kind of gospel-chorus chant of "Love is in the house" that grew into seven-part harmony until it segued deftly into the Twinemen’s "Harper and the Midget," a colorful slice of Southern life based on Lewis Nordan’s novel Music of the Swamp. Mazzone’s bass gave the tune a hard, propulsive edge as Colley’s sax pushed the envelope, twisting the already circuitous sax lines he plays on the CD into something approaching Eastern modality. He also used a delay pedal to end the tune with the equivalent of chirping saxophone feedback.

Next Delmhorst stepped to the microphone for "Little Wings," a song from Five Stories. As Colley switched to clarinet and Barry traded his Telecaster for a lap steel, Delmhorst captivated the room with a voice as clear and powerful as Sargent’s. Their differences — Sargent is a supple vocalist with an improviser’s instinct for melodic phrasing whereas Delmhorst is a more traditional singer with a country/folk orientation whose tone rings with sweetness — might have been the most sparkling ingredients of the night’s harmony singing, which was fortified by Cavanaugh’s dusty twang and Kimball’s sharper tones and phrasing.

Cavanaugh, who also has a solo CD out, stepped up for his own ballad "We Should Have Waited till April," injecting the first taste of hardcore country into the night. Ryan continued the streak with "This Town," an original tune from his debut that displayed his dark sense of humor in its mix of alcoholism and lost love, as well as his mandolin chops. With Conway and Beard switching between a full drum kit and a percussion set-up of congas, cymbals, and other instruments, everything was delivered with a rhythmic authority that encouraged experimentation. As Delmhorst sang a dark ballad, for example, Colley and Barry wove layers of menace through the room with slightly askew sax lines that entered off the beat and guitar volume swells that sounded like distant banshee wails.

As the first set went on, the game of lead-singer round robin continued. In the second set, each vocalist held the microphone in turn for two songs, and even Colley took the spotlight, singing the Twinemen’s "Learn To Fly." Cavanaugh, Kimball, and Delmhorst all offered outstanding material, but the music had the hardiest pulse whenever the Twinemen’s writing got flexed. "Ronnie Johnson" was especially commanding, with Conway’s breath-like playing driving Sargent’s soaring evocations of obsession and Barry’s solo, which straddled blues patterns and Middle Eastern melodies.

The night’s most poignant moments may have belonged to Conway, who finished the evening by leaving his kit for the centerstage microphone and grabbing a guitar along the way to lead the group in "Who’s Gonna Sing." The tune, which also concludes The Twinemen, invoked the spirit of the night’s missing family member, the late Mark Sandman, who led Morphine, built High-n-Dry, and had associations with many of the people on stage. Conway’s shakiness as a singer and guitar player underlined the song’s fragile emotions. "What if I wake up/And the music stops playing/And the record’s all done/And the red light’s still on" seems a metaphor for Sandman’s passing and the consequent need to throw off the burden of sadness and continue. The song resolves with the advice "Don’t be afraid/Step into the sun," voicing a pledge to move on despite the loss of Morphine’s unique musical chemistry. And indeed, Conway, Colley, and the rest of their musical family have.