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.