The Weekend's Viewing: Gary Barlow: On Her Majesty's Service, Sun, BBC1 How to Paint a Queen: a Culture Show Special, Sat, BBC2

You may have noticed that being a member of the Royal Family considerably lowers the bar when it comes to some kinds of excellence.

A remark with even the faintest trace of flippancy to it becomes a "joke" or a "witticism" in the mouth of a royal, while courtesies that would be common from any commoner are transformed into evidence of an almost supernatural graciousness. Even allowing for that effect, though, it was a bit of surprise to discover from Gary Barlow: On Her Majesty's Service that Prince Charles is an expert in world music. Gary and Lord Lloyd-Webber had been commissioned to produce an anthem for the Golden Jubilee and after a swift head-to-head session at two grand pianos to lick out the basic melody, it was Gary's job to record Commonwealth musicians for the final mix. But before he went, he drove off to Highgrove for an audience with Charles: "We're hoping to try and get some guidance," he said, it having apparently been decided that two of the biggest selling composers of recent history could use some tips from the heir to the throne. Charles played him a CD of Xhosa click-singing ("Marvellous!") and suggested he go off the beaten track.

When Gary looked at a map he seemed a bit daunted "The Commonwealth is massive, right? I mean massive! Massive massive." But he set off anyway, starting in Kenya at the Treetops lodge where the young Princess learned that she'd just become Queen. Trundling around in a Land Rover, humping his own recording equipment, Gary laid down samples of schoolgirl choirs, a local nyatiti maestro ("I busked for about four years in London") and a Kibera percussion ensemble who called themselves the Slum Drummers. In between recording sessions, Gary rhapsodised, just a little too often, about how memorable and moving every experience it had been: "I feel motivated now to get on a plane and finish this record," he said after meeting the Slum Drummers. Really, Gary? You were just about to chuck it in otherwise, were you?

It was a mistake of structure rather than of character, though. "I see congeniality in that person," declared a Rastafarian priest in Jamaica's Blue Mountains (where Gary had gone for a bit more drumming) and he was right. Barlow is perfectly nice and it wasn't really his fault that his post-match comments eventually started to sound a little royally bland themselves. Or that once Gareth Malone's Military Wives choir had been added into the mix, the various Commonwealth contributions he'd worked so hard to acquire became virtually inaudible. Her Majesty, you will be relieved to know, thought the song sounded very nice when Gary, Lord Lloyd-Webber and Gareth played it to her at Windsor. Personally, I'd have given them a regal dressing down for rhyming "clearer" with "hear ya", but I don't suppose she got where she is today by picking fights.

At the beginning of How to Paint a Queen: a Culture Show Special, Alastair Sooke claimed that there are more images of Queen Elizabeth II than any other person in history. I lost the next five minutes because I was trying to work out how the hell he could have established (or verified) this impressive sounding fact. But when I tuned back in again it was to a perfectly serviceable account of royal iconography, from Elizabeth I's knowing creation of the Virgin Queen to the current Queen's broad mélange of unposed photography and formal portraits. Curiously, Sooke didn't identify, or directly address, one of the most unusual portraits of the current Queen seen in his programme – Chris Levine's extraordinary portrait of her with her eyes closed. It's titled Lightness of Being, which is a bit of a liberty, but it does have a rare and vulnerable quality to it, as if she's briefly resting from the overwhelming business of being who she is. After this weekend, who could blame her?