I haven´t listened to the podcast yet, but have been thinking about the concept a lot. Even when relatives sing the same line without harmonies, it´s a great double track. And with harmonies, magical. Some of my favorites:
Let´s not leave out twins:
And any excuse to mention Mother Maybelle, June, Anita, Helen:
At UT Hootenanny! Did they ever play with Renfield?
Goosebumps.
And don’t forget these guys!
The double pompadour! So good.
Going to put the Gibb Brothers on this list. Please to enjoy extremely young vintage.
Good call!
Also the Wilson Bros. My dream is to find video of amazing falsetto Brian combined with Pet Sounds-era Carl, but I’ve yet to find it. Brian stopped touring by then, and all the early videos don’t feature Carl at his finest. But enjoy a bassist who sings lead, and cousin Mike emanating “creepy uncle” from a young age on Ed Sullivan.