There is nothing quite like a BBC4 documentary to shake you out of your complacency. Take Chas and Dave – Last Orders, for example.

I had hitherto been quite happy to dismiss Chas and Dave as a novelty act, albeit one that had enjoyed enormous success and longevity. This is, after all, the duo responsible for supplying Tottenham Hotspur with several FA Cup singles, one of which included the immortal lines “Ossie’s going to Wembley/his knees have gone all trembly”.

But what do you know? It turns out that Chas and Dave are not only feted within their industry for their songwriting and musicianship, but also widely celebrated as heirs to a working-class, singalong musical tradition that harks back, through the pubs and clubs of the last century, to the days of the Victorian music hall.

Who says? Well, such diverse and authoritative contributors as Roy Hudd, Phill Jupitus, Jools Holland and Pete Doherty. Indeed, the former Libertines’ frontman had to stop filming at one point, overcome by tears at the recollection of a particularly poignant, granny-related Chas and Dave lyric – although whether he was under the influence of pure emotion, or something imbibed or ingested, remains open to question.

What’s more, the history of Chas and Dave is the history of post-war popular music in Britain. As session musicians or as a support act, they have at one time shared a stage with Jerry Lee Lewis, Gene Vincent, Led Zeppelin, and the Beatles. Indeed, in their very early days the fab four provided the support to Chas’ band the Outlaws.

But in terms of credibility, even this fades to insignificance compared to the events of Christmas Day 1982, when Chas and Dave played an integral part in both the BBC and ITV evening schedules. Viewers could choose between watching the original article in their own singalong special, or The Two Ronnies pay tribute by way of a brilliantly observed and uncannily executed musical pastiche.

After watching Last Orders – the title refers to Dave’s recent retirement from touring – it would be churlish to deny them anything less than musical legend status.

Moreover, they came across as unpretentious, honest, charming and intelligent guys. Among many highlights in this fascinating documentary was footage of a breakfast TV interview conducted by a clearly bewildered Selina Scott.

“Why do you wear braces?”, she asked our blue-collar troubadours.

Allowing just the slightest pause for effect, they spoke as one: “To keep our trahsers up.”

The Thick of It placed its sundry spinners, movers and shakers under the spotlight of a public inquiry into parliamentary leaks. With the characters facing interrogation, and on their best dissembling behaviour, this one-hour special might have been short on the visceral and occasionally poetic profanity for which the show is celebrated, but it still contained a wealth of memorable lines and great performances to enjoy.

We were also afforded the rare sight of Malcolm Tucker (Peter Capaldi) struggling, and signally failing, to squirm off a very nasty hook.

Chas and Dave – Last Orders, BBC4, Friday, October 26, 9pm
The Thick of It, BBC2, Saturday, October 20, 9.45pm