I caught part of President Donald Trump’s Tennessee speech this week on the president’s favourite channel, CNN. These days his rallies open with “Hail to the Chief” but they still close—this week’s one in Nashville did, at least—with the song he used throughout the campaign: the Rolling Stone’s 1969 classic, “You Can’t Always Get What You Want.”

It might be the economics profession’s favourite song. A fellow I knew, the late Lawrence G. Hines of Dartmouth College, used it as the inscription for his elegantly written 1977 microeconomics text, The Persuasion of Price. The foundation stone of economics is that people can’t always get what they want. Maybe Mick Jagger learned that in his brief stint as a student at the London School of Economics.

But it’s a very strange choice for a campaign song. Politicians usually spend most of their time telling people they don’t have to make choices, they can always get what they want. Since first hearing it used to close a Trump rally I’ve wondered what its use is all about—unless the intended message is mainly subliminal: Trump’s campaign is unusual so his choice of campaign song is going to be unusual, too. Unusual rules here.

It’s still a weird choice, though, and for many reasons. The Rolling Stones were the black hats of 1960s rock compared to the white-hat Beatles. Mick Jagger and Keith Richards are—or were—notable roués. Jagger has eight children with five women. Yet the Trump campaign was trying to and did appeal to born-again Christians. Moreover, the Stones are an English band. Jagger has dual citizenship but he’s Sir Mick and unmistakably British. The royalties, if any are paid, may therefore be an imported service, a no-no in Trumponomics. (You’d think royalties would have to be paid—the Stones officially disapproved of Trump’s use of their music.)

Then there’s the song itself. It starts with the London Bach Choir singing a choral refrain about meeting a woman at a reception who is carrying a glass of wine in her hand and is about to meet her connection. Not very born-again! The second verse is about going to a demonstration, the third about meeting a guy at the Chelsea drugstore, the fourth and final about the woman at the reception again but this time she has (unwholesomely) blood-stained hands and, Jagger concludes, “She was practiced at the art of deception”—which, when you think of it, doesn’t actually seem out of place at a political rally.

But then there’s the chorus: You can’t always get what you want but if you try some time, you just might find you get what you need. As I say, we economists love the emphasis on limits. Politicians? Not so much. Though he hasn’t been a politician long, Donald Trump seems even less focused on limits than the average practitioner of his new trade. His policy for Obamacare was to replace it with something better, cheaper and completely universal, a promise he’s currently having trouble delivering. (“Nobody knew health care could be so complicated,” he said recently, though in fact just about everyone he ran against completely understood its complexity.)

And what exactly did the song mean in the context of presidential politics? I may not be the candidate you want, but I’m the candidate you need? It’s an unusual pitch. And Trump was not known during the campaign for conceding people might not think he was the best candidate but rather the candidate they needed. It was clear from the start he thought he was both best and most needed.

The use of the song, like much about Trump, his campaign and his presidency, is full of contradictions. On the other hand, if the background noise in a political rally is repeating the message that you can’t always get what you want, that’s probably a good thing.

Trump might want to diversify his musical selections, though. When Congress turns to comprehensive tax reform later this year, he might try “Taxman” from the Beatles’ 1966 album, Revolver: There’s one for you, 19 for me, ′cause I’m the taxman.