Yeah I know it wasn't public as such but like here in the UK back then, tickets would have been free if you knew the right people...I was unfortunately too young to go to that one with Zep.
Edit: It was not a public concert. It was for the Danish television.
Did you know that the first ever public concert with Led Zeppelin was on september 1968, where they played at Gladsaxe Teen Club at Egegårds school in Gladsaxe, Denmark.
So they went to Gladsaxe twice in a year and a bit? Didn't know that!