A slide presentation directed by Anders Hanser (pictures) and Peder Wistedt (programming) consisting of hundreds of stills taken by Anders Hanser from the 1979 concerts (which is why it's listed in 1979 and not 1980 when the song came out) which was used as the official PROMO clip (with additional verse and chorus starting, "Standing up is scary if you think you're gonna fall.").

The first time most of us saw this was on the Words and Music programme on the television in 1981. This original version, released on the ABBA Music Show 2 video released in early 1981, had the images matching the lyrics in certain places in timing.  At the time it was the only place to see and hear the full song (with the extra bridge) and to have it all in sync.

Future releases messed up the synching of images with sound because of the change of speeds from 24 frames per second to 25 frames per second and back again when they were trying to sync up better quality audio than was heard in the 1981 VHS release.

When it was included on More ABBA Gold they redubbed it into stereo, but because they couldn't locate the tape with the extra verse, a very clunky extension was made to the sound which didn't match the imagery at all.

When The Definitive Collection came out the correct audio was there but it was still completely out of sync.

The Essential Collection finally corrected the pitch meaning that it was finally and beautifully restored - but still only in mono and also in NTSC.

So it still needs to be re-done in stereo since they finally located the full stereo recording which appears on Super Trouper Deluxe Edition.

The Agnetha / Benny / Bjorn / Frida parts were re-used in the 1992 Dancing Queen PROMO.

Lyrics available on the Official ABBA site

Thanks to Alex Jones, Trent Nickson and Ian Cole.
Some information from ABBA Magazine No.36.
YouTube link c/o AbbaVEVO