What does Allsång mean?
Allsång translates roughly as community singing or a bit of a singsong. The annual summer singalong that is Allsång på Skansen has proved a huge success since it was first televised in 1979. It is known to inspire fellowship, unity, good cheer and sometimes even violence. But more of that anon.
So what happens exactly?
What happens is that national broadcaster SVT books up a range of musical artists who convene once a week at Skansen to perform on the Solliden stage.
The professional performances are then interspersed with songs led by the presenter or choir leader, who whips a crowd of pensioners into a full-throated frenzy as they belt out well-loved songs about attractive places, lovely flowers and chirping birds.
Also expect large groups of young teenagers hoping to get a glimpse of their favourite artist.
That sounds very nice.
It is positively spiffing. In fact the whole thing is so overflowing with cuddly niceness that it can drive a certain kind of person into paroxyms of rage.
As a case in point, one viewer became so incensed on the opening day of one year's Allsång season that he threatened to sabotage the entire extravaganza.
While hardly commendable, news of such behaviour will cause a ripple of guilty delight among many of those not counted among the two million or so viewers who swear by a weekly dose of the stuff.
Who presents it?
Swedish singer Sanna Nielsen. She took over from Eurovision heartthrob Måns Zelmerlöw, who in turn took over from comedian and former reality TV presenter Anders Lundin.
They've all had big shoes to fill. Before them the show was hosted by, in order from the start, Sven Lilja, Egon Kjerrmann, Bosse Larsson and Lasse Berghagen.
The latter is probably the one most Swedes associate with Allsång. From the moment Berghagen came aboard in 1994 (and stayed until 2003) the hugely popular singer and composer got everybody singing from the same hymn sheet, which inevitably means all successors get compared to him.
What sort of acts turn up for the singsong?
Until the turn of the decade the line-up was dominated by Swedish artists of the schlager persuasion.
But ever since Ricky Martin brought his vida loca to the serenity of Skansen in 2001, a regular infusion of modern chart music has caused the younger generations to commingle with the elderly in a display of rare solidarity.
Who's going to make this summer a televisual must?
The festival will offer its audience and the millions of viewers at home several big names from the Swedish music scene including Icona Pop, Mando Diao, Danny Saucedo, Lisa Nilsson and Jack Wreeswijk.
It also regularly features a number of Melodifestivalen artists.
Big names indeed. There must be a signature tune for an undertaking of this magnitude?
Yes, there is. Every week the gathered masses join for a rendition of a song called 'Stockholm in my heart'. The original theme song went: 'Sing along, sing along, with your television, it will turn us into a united nation'. But that didn't last.
Amazing they didn't keep that one. It sounds tremendously catchy.
More information on this year's dates and artists at the Skansen website
Article first published in 2012 and updated in 2017.