It's Boston in their prime and in their home town! The crowd was rowdy and the band fed off of that. Tom Scholz even instructed the crowd to ignore the rules and stand on their seats if they wanted to.
This recording was widely traded for years on cassette, and eventually released on a bootleg CD called "Party to Boston". But finding a good audio source proved difficult. This is a 2nd gen cassette tape which sounds way better than any tape of this show found previously... and sounds *much* better than "Party to Boston" (which is even missing a song).