Coleman Williams is the son of Hank Williams III, the grandson of Hank Williams Jr. and the great-grandson of Hank Williams Sr.

The poster for Sunday night’s show at Volcanic Theatre Pub in Bend touts Coleman Williams as one of the artists performing. His name encircles a large “IV” — as in the Roman numeral for the number four.

What does it all mean? Well, Coleman Williams is the son of country-punk rabble rouser Hank Williams III, which is why he calls himself IV. And as you likely can guess, Hank Williams III is the son of outlaw country giant Hank Williams Jr., who is the son of Hank Williams Sr., arguably the most important and influential country music artist of all time. Hank Sr., in other words, is Coleman’s great-grandfather, and Coleman’s got some impressive bloodlines. (He sounds more like Hank Sr. than either Hank III or Hank Jr., if you’re wondering.)

There’s another name on the show poster, too: Lightnin’ Luke, an itinerant singer, songwriter and fiddler who is also a member of Portland-based folk-punk faves Bridge City Sinners. As a solo act, he leans heavily into raw Southern blues, folk ‘n’ soul. No word if he comes from a long line of musical legends, but he’s good at what he does, so you should make sure to get to Volcanic to see him, too.

Lightnin’ Luke and Coleman Williams: 8 p.m. Sunday, doors open 7 p.m., $18, Volcanic Theatre Pub, 70 SW Century Drive, Bend, volcanictheatre.com.