Looks like a great time. The music era is right up my alley, although I listen to a wide variety of stuff. The vocals arent spot on but they are doing so many different bands/acts.
Tribute bands are usually specific to a band. Many moons ago the crew I was with was staying in San Diego and there was a local bar nearby featuring a Beetles tribute band. These dude were awesome...I mean perfect. When they took a break, we took them to our hotel room and got them "smoked up", if you catch my drift. It was hilarious, they went from pitch perfect to couldn't remember the songs when they started back up!
Sorry...not sorry! Yes, it screwed it up for the other patrons, the bar and the band but its a memory I'll never forget!
This Hairball looks like a good time if you take it for the spectacle it is supposed to be and dont be too critical about how close their vocals are to the original.