“Do you remember/ The 21st night of September?” We certainly do, thanks to Earth, Wind & Fire’s ever catchy “September,” a pop-funk hit that missed its target date by several weeks, hitting airwaves at the end of November 1978 and changing the minds of pretenders on its way to a No. 8 peak position in early ’79. There are some great period effects in this spangled, spirited and skulleted video, even if Doug Henning is sadly absent.