Which of these sentences is punctuated correctly?
Although the concert doesn't start for over an hour; most of the fans have already arrived at the concert hall.
The concert doesn't start for over an hour; though, most of the fans have already arrived at the concert hall.
Most of the fans have already arrived at the concert hall; however, the concert doesn't start for over an hour.
Even though the concert doesn't start for over an hour; however, most of the fans have already arrived at the concert hall.