Ah, this was overdue proper canonisation. The loose theme behind this third special gap-filling week of Canons is awkwardly stranded between the novelty theme and the let's-do-the-show-right-here thematic that lies behind this entire series. Basically, it's people who may never have expected to appear on Top Of The Pops and now they're there were going to make something of it for themselves. The omega of this is surely Otway's first of three appearances, one in which the audience are the very definition of not being able to turn away.
The second appearance involved Elton John confusing himself, more Otway perambulation and a not unreasonably swelling audience. Twenty five years later he got to confuse Richard Blackwood, which is never a bad (or difficult) thing.