Thought it's worth mentioning that on the 3/11/83 episode, that we will seen on Friday 5th May, the Elton John studio performance of 'Kiss The Bride' is accompanied with 4 dancers behind him, 2 of whom were Zoo regulars. If this was provided by his record company, then it would be a first for him, as far as previous TOTP appearances. If they were brought in by the show then there is no mention of a Dance Director in the end titles, but there is a 'staging, costumes and make-up' person given just after the usual 'gallup chart' section.
I remember hearing the news and not being bothered in the slightest, a complete opposite to the end of Pan's People and Legs and Co. Whilst I did eventually warm to them a bit after about a year they had become such a bit part at the end that there wasn't much to miss.
And if you're asking me when, I'll say it starts at the end.