Question: what connects Blue Peter with Black Sabbath guitarist Tony Iommi's fingertips? Answer: a bottle of Fairy Liquid.
The venerable children's programme showed young viewers how to make everything from a model rocket to a fully functioning thermo-nuclear device using just an old washing-up liquid bottle and some sticky-back cardboard.
Iommi -- who used to wield a welding torch in a dark, satanic mill before going on to wield an axe in a dark, satanic rock band -- went one further: he made himself new fingertips out of the top of a Fairy Liquid bottle and bits of an old leather jacket after his real ones were chopped off in an industrial accident.
We were into the second part of I'm In a Rock 'n' Roll Band!, a kind of television compilation album of clips, quips and anecdotes from old hands at the business end of the rock'n'roll business. This week's subject was lead guitarists, who, by consensus, are the coolest dudes in any band.
"The genius is really behind the guitar," drawled the spectacularly hirsute Billy Gibbons of ZZ Top (and in Billy's case, behind the beard as well). The lead singer, said the no-nonsense Richard Hawley, usually "has an ego the size of Saturn" and generally thinks he knows better than the guitarist.
The Police's Andy Summers illustrated this by revealing that the egotistical Sting had originally intended playing the brilliant Roxanne in a bossa nova style.
But how is a guitarist to make himself noticed when the singer is grabbing the lion's share of the spotlight -- and the groupies? Slade's Dave Hill got around the problem by planting his silver platform boots atop a mountain of guitar risers, meaning he towered over Noddy Holder (even with the hat).
The amazing Wilko Johnson, formerly of Dr Feelgood, took a more direct approach. He fitted his guitar with an extra-long lead so he could skitter jerkily across the length of the stage, right in front of singer Lee Brilleaux.
If the relationship between singer and guitarist is doomed to fracture eventually, the obsessive love affair between guitarist and his instrument is unbreakable. Jimi Hendrix used to bring his to the toilet with him, recalled Jeff Beck. "I began to feel relatively normal," he added, deadpan.
I'm In a Rock 'n' Roll Band! is wonderful stuff, the kind of thing the BBC does better than anyone else, and I'd have greedily lapped up another hour of it.
Pity you can't say the same for the self-indulgent, 20-minute solos old-fashioned guitar heroes were prone to. As Richard Hawley put it: "There's a difference between exploring musically and someone going on a voyage up their own a**e." Kerrang!
There was a moment in Aftershock: Ghost Land in which the camera switched to infra-red to reveal the lack of lighting in one of the country's countless half-finished ghost estates.
It was reminiscent of one of those cheesy Living channel programmes featuring 'medium' Derek Acorah, except the lost souls haunting these places are very real, and very angry. We all should be angry. Surveying the wreckage left by banking greed and political incompetence made you want to take "the two Brians and the three Marys", as one young wife facing negative equity called them, clamp their eyes open, Clockwork Orange-style, and force them to stare at the reality until their eyes bleed.
I'M IN A ROCK 'N' ROLL BAND! *****
AFTERSHOCK: GHOST LAND ****