The Black Dog is more than a restaurant-it is an institution. I have been coming to this place since I was 19 and I loved it from when I walked in... And was promptly told to remove my hat. Being 19 at the time and not wanting to drink where ill-mannered young people (my peers at the time) were this was perfect. I gladly removed my hat and sat down and have been periodically visiting ever since.
They still have great live music and friendly staff and the food is still good. This is not a fine dining establishment and that is just fine. I have never had something I disliked even if I have had better elsewhere. That is a good sign because they don't just focus on a few signature dishes but do everything well.
It is also worth trying their local brews. They are wonderful and the price is good.
At the very least come and give it a try and just take in how happy everyone around you is.