THE 2022 edition of the Glastonbury Festival gets underway on Wednesday.

More than 200,000 people are set to descend on Worthy Farm in Pilton for the event - the first since 2019.

Each reveller will go forth with lineup in hand and a mental checklist of the acts they hope to see over the next five days.

However, as always there are a few blanks left to be filled.

READ MORE: Tesco & Sainsbury's in Somerset gear up for Glastonbury Festival

READ MORE: Charge your mobile at Glastonbury Festival 2022 - here's how

Glastonbury TBC slots

Dotted throughout the schedule are times slots where no act has been detailed as performing.

Instead of a named artists, some time slots are simply filled with TBC (to be confirmed), or TBA (to be announced) - while others go all out and promise a 'special guest'.

While this may be more common on some of the outlier stages, when such gaps appear on the larger venues, it provokes a lot of excitement among Glastonbury-goers.

Who has played secret sets at Glastonbury?

South Wales Argus: The band Elbow previously played a 'secret set' on The Park stage at Glastonbury. Picture: PAThe band Elbow previously played a 'secret set' on The Park stage at Glastonbury. Picture: PA

Previous 'special guests' include Radiohead's Thom Yorke and Jonny Greenwood, Elbow and Biffy Clyro - all of whom have graced The Park stage.

In 2017, The Killers turned up for a shock performance on the John Peel Stage, drawing a massive crowd to a relatively small venue.

And in 2014, George Ezra - more on him later - turned up for an early-evening set on the BBC Introducing Stage, more used to hosting up-and-coming performers (including George himself at a previous festival).

So, these things mystery slots can be well worth taking time out for.

'Secret' sets at Glastonbury 2022?

Without focussing on smaller stages, there are still a number of slots yet to be announced at some bigger venues.

Here are a few worth keeping an eye on:

Thursday: William's Green: 7.45pm-8.25pm

Friday: Arcadia: 11pm-1am

Saturday: Greenpeace Stage: 8.45pm-9.30pm

Sunday: The Park: 6.15pm-7.15pm and John Peel Stage: 2pm-3pm

Who is playing secret sets at Glastonbury 2022?

Sometimes, secret sets are exactly that, and they don't leak.

However, there is usually some savvy marketing work done before the performer takes to the stage, for one thing, to ensure they get a decent crowd, which means folks generally learn of an act at least an hour before the show.

A couple of hints have already been leaked, giving us a pretty good idea of who might be filling some of those slots.

The Chemical Brothers - Arcadia

The dance duo are Glastonbury favourites, having played numerous times to rave reviews in the past.

It was something of a surprise they weren't on the original line-up, so don't be surprised if they appear in that Arcadia slot on Friday night.

How do we know? Well, the duo recently tweeted about seeing fans 'in a field' soon - and retweeted a post from a Glastonbury devotee suggesting an appearance in Arcadia, cementing the rumour.

George Ezra - John Peel Stage

Yes, George again. Another one surprisingly missing from the line-up announcement, particularly after a well-received appearance at last year's Live in Worthy Farm show.

The songsmith is looking likely to fill the Sunday afternoon slot on the John Peel Stage.

How do we know? Well, one rather careless (or clever, depending on your viewpoint) snap from the Glastonbury site showed an innocuous-looking sign.

But eagle-eyed Ezra fans soon clocked the sign's meaning.

It read: 'Gold Rush Kid, John Peel Stage, 2pm'.

What's the name of Ezra's new album? You guessed it, Gold Rush Kid.

Other names being bandied about:

Green Day

This is a hark back to the pop punksters' frontman, Billie-Joe Armstrong, visiting the festival back in 2019.

The East Bay rockers are in the country - they are playing in Huddersfield on June 25 (Saturday) and Dublin on June 27 - and one of their support acts (Amyl and The Sniffers) is already on the Glasto bill.

Jack White

The former White Stripes guitarist is also in the UK this month, with shows in London on June 27 (Monday after Glastonbury) and 28, so could well be at Worthy, but will he play?