If you're just listening to the music... It's blues with electric guitar. Think Robert Cray, Stevie Ray Vaughn, Clapton, BB King. Performance was very deep and soulful; I would picture an old African-American man on a
porch in Mississippi singing about his adverse life experiences (backed by a wailing electric guitar).

However, if you're actually looking at the musicians... Back Door Slam is comprised of 3 white British guys who are barely in their 20s. The bassist looked too young to shave.

I was shocked, but in a good way. These guys are talented. Check 'em out.