The forward march of Blue Peter feels like it has, for the time being, halted.

A dip into its present incarnation reveals a programme peppered with anxiety masquerading as hyperbolic shouting. Too many faces have been too rapidly replaced; too many motifs have been too forcibly mangled. This elegiac tribute rightly acknowledged its heritage as an indispensable institution. But Blue Peter, at the moment, is neither of those things. There’s virtually nothing within the fabric of the show to distinguish it from any other kids’ entertainment series. And it’s certainly no longer an institution.

Matriach of Studio One and supply teacher to the nation

Does this matter? As long as people have eyes to see there’ll be someone watching the BBC’s longest-running children’s franchise. And there have been serious wobbles before, characterised by the same hasty shedding of personnel (the late ’70s) and unfocused makeovers (the early ’90s).

Just at the point in proceedings when salutations like this seek, and usually fail, to persuade you the subject in question is healthier than ever, in stepped Janet Ellis. Seconds before the closing credits rolled, she insisted: “The modern child still finds the sense of discovery in things that Blue Peter reflects, and I think that’s an extraordinary ability”.

Her pedigree urged the viewer to treat her views with hushed authority. But though her argument in itself was sound, the preceding 59 minutes of television seemed concerned with something else entirely – namely, the eulogising of faces and places long gone. Blue Peter at 50 was a totaliser-sized doff of the hat to how we used to live, but with scarcely a polite nod to where we go from here.

A snake does a piss; Konnie makes sure we all know

The celebration of memory is a tricky one to pull off. You need poise, intelligence and a killer cast list. What you don’t need is clutter, waffle and people who had nothing to do with the matter in hand.

At least this enterprise made sure it had the right tools to finish the job. No diversions into unrelated anecdotes. No tangential clips. And, mercifully, only a few contributions from celebrity viewers.

Nobody needs to be told what to think about the history of Blue Peter. All that’s required are the people who were there, both then (in the form of highlights from the archive) and now (contemporary interviews). Both were on offer here in plentiful abundance, and to the exclusion of almost everything else. Including any or all sense of chronology.

Biddy in action: "Apply your mind & stop panicking"

When, a minute in, the programme lurched forwards 30 years, then back 10, then forward 25, before any mention had been made of how Blue Peter even began, at least one viewer felt a palpable queasiness that was more than just motion sickness.

Surely this wasn’t just going to be another exercise in nostalgia-by-numbers? Was it all going to be just pissing elephants, lifeboats and Mark Curry mishandling Lego?

Such concerns were misplaced. Yes, there was no order to the thing. Sure, it was as scattershot as it was selective. But with such rich pickings up for grabs, it was impossible to feel discomfited for that long.

For the old Blue Peter magic soon began to work. Incidents and epiphanies shuttled past, triggering emotions long buried. Even the very look of the old show, the bareness of the set, the colour of the cooking utensils, the sound of a dog barking from across a cavernous studio floor… these revealed themselves to have immense associative power. This was the stuff teatime dreams were made of.

Pete nobly steers the subject away from Shep - again

If you surrendered yourself and your 21st century scruples, and weren’t bothered by quirks of editing or narration that went nowhere (asking questions – “What made it so special?” – that were never answered), few faults could be found.

Almost every presenter had been rounded up; many were reunited for collective reminiscences both ribald (Duncan/Greene/Groom) and crotchety (Singleton/Purves/Noakes).

These were great fun and could have formed an entire programme in themselves.

Peter Duncan recalled blithely dishing out badges to plumbers and builders. Peter Purves earned the right to become the next prime minister when he berated John Noakes for droning on about Shep.

"Our fans? I can see four, Miles"

Anthea Turner summed up her entire existence in a flash when she casually declared her house possessed “a craft cupboard”. And Lesley Judd struck the most wistful note when she concluded: “I lived an entire life in seven years”.

A hand of forgiveness was even extended to the Cheech and Chong of BP folklore, Richard Bacon and Stuart Miles, who were allowed a few moments’ air time to ruminate awkwardly in the Blue Peter garden. This wasn’t a tribute about to bury any less than dignified episodes in a subterranean time capsule. Well, apart from Michael Sundin.

No, Bacon’s sacking was covered, as was the bogus telephone call from a competition entrant, as was the rigging of the cat-naming public vote. Richard Marson, on whose watch the latter two occurred, pleaded that a “mistake is very different from a wilful mindset where you think the audience don’t matter”.

Richard Marson: "It wasn't me, guv!"

This sounded like a dash of whitewashing. Few could ever accuse anybody who either appeared on or worked for Blue Peter of not acknowledging the audience. Marson’s error was thinking they mattered too much, to the extent of wilfully misleading them for fear of acknowledging that things go wrong on live television.

As the clips confirmed, up until a year or so ago Blue Peter had nothing to fear. It had adapted itself to a multi-channel, interactive world. It had found a fresh way to serve up that familiar rich mix of fun and education.

And it had enjoyed a run of presenters remarkable for consistency of entertainment and capability. It’s telling that, of the show’s two best ever hosts to date, one hails from the last decade (Matt Baker – the other being Sarah Greene). 

Just another day at the office for Matt Baker

Yet when the only real reason for something to exist is for the sake of it, that’s no sane reason at all.

Apart from that valediction from Janet, not a breath was spared on the consideration of Blue Peter‘s current form, let along its future.

If the show is to have a future worthy of its past, it needs to pay more attention to the values on display during this superb, evocative excavation. Otherwise, while the idea of “Blue Peter at 100″ sounds tantalising, the reality of watching a second half-century of clips is bone-chilling. 

In the words of Biddy Baxter: just apply your mind and stop panicking.