John Paul Jones hasn’t been touring regularly and releasing albums for the past few years. Instead, he has spent years working on an opera based on an obscure Swedish play. Here’s everything we know so far about John Paul Jones’ upcoming opera.

It’s based on a Swedish play

Jones has explained in interviews that his upcoming opera is an adaptation of “Spöksonaten” (“The Ghost Sonata,”) a play written by Swedish playwright August Strindberg in 1907.

The play is about a student and the people who live in a fancy apartment building in Stockholm. A mysterious character in a wheelchair named Jacob Hummel allows the student into the building, but then the student finds that everything inside the apartment is hellish.

The play explores themes like the supernatural and the class divide. Here’s how Jones described the play in a June 2016 interview with Tight But Loose: “It’s a psychological drama — it’s very dark there are a few comic moments in it but not too many.”

He’s been working on it since around 2010

Jones has spent years perfecting his opera. He began talking about it more publicly in 2013, but evidence online shows Jones has been in talks about the project since at least 2010.

Here’s a fascinating video from 2011 showing Jones meeting with theatre and opera director Gerald Thomas and Helen Cooper to talk about his early plans for “The Ghost Sonata”:

John Paul Jones, Gerald Thomas and Helen Cooper from The Dry Opera Co. on Vimeo.

He changed what the opera was about

Jones told Tight But Loose that “I began thinking thinking about it at the end of the Crooked Vultures. I had an initial idea but then a year later I changed the subject as I wasn’t happy with it.”

Intriguingly, it looks like we can tell what Jones’ abandoned idea was. A video posted to Vimeo a year before the one embedded above shows Jones discussing a different opera with Gerald Thomas.

Gerald Thomas and John Paul Jones from The Dry Opera Co. on Vimeo.

This video shows the pair talking about a short story called “The Judge’s Wife” by Chilean-American author Isabel Allende. They discuss making changes to the story, including changing the character of Vidal from a bandit to a drug lord. Jones also mentions making Vidal the illegitimate son on the judge in the original story.

Thomas says as the video ends that the meeting took place at the Hoxton Hotel in London, and also claims that HSBC had agreed to fund the opera.

A “big star” may be involved

Jones said in an interview with Led Zeppelin magazine Tight But Loose in June 2016 that one of the two lead singers for the opera is now “a big star” but wasn’t when the project started. He declined to name exactly who the singer was, though.

NEW: John Paul Jones says in the new issue of Tight But Loose that a “big star” is involved in his opera pic.twitter.com/HGNeQj6w83

— Led Zeppelin News (@LedZepNews) June 1, 2016

John Paul Jones likes contemporary operas

Jones hasn’t developed a sudden love of opera — he has liked them for years. In June 2013 he went with his wife Maureen to the opening night of “The Perfect American,” an opera by Phillip Glass.

PHOTO: Last night John Paul Jones attended the first night of ‘The Perfect American’, an opera by Phillip Glass. pic.twitter.com/xvqvGrP4N3

— Led Zeppelin News (@LedZepNews) June 2, 2013

John Paul Jones has been closely overseeing the soundtrack

Jones has been repeatedly photographed overseeing the orchestration for his opera. It seems like he has been very closely involved with the soundtrack.

PHOTO: John Paul Jones photographed last week working on the soundtrack for his opera (Instagram/james_clarkez) pic.twitter.com/Mtc8FxGCnJ

— Led Zeppelin News (@LedZepNews) September 1, 2015

Jones told Tight But Loose that “it’s two hours and 40 minutes of just music at the moment — there will be some singing, obviously, but it’s a lot of music. I’ve not written that much music for one project for a long time and it’s a full 60 or 70 piece orchestra with six main singers.”

NEWS: John Paul Jones has just released a photo of himself working on the score for his upcoming opera pic.twitter.com/nkqZbuQLrv

— Led Zeppelin News (@LedZepNews) August 24, 2015

It has been delayed …

Clearly it has taken a long time for this opera to come to fruition, but it seems like it is taking longer than Jones first thought. He said in 2013 that he had finished the first act, and in 2015 he said his opera would be performed next year. In another 2015 interview he said “several opera houses” were interested in his opera.

The most recent update we have on the timing of Jones’ opera comes from the Tight But Loose interview in June, where Jones said that “I’ve just about finished it. All the orchestration is done now so I’m talking to opera house directors. There are several interested, so hopefully we can get it off the ground real soon. It will probably be next year when it goes into an opera house.”

… but it has arrived with the publisher

John Paul Jones’ Twitter account has liked a tweet from May 22, 2016 showing Jones celebrating handing over the opera to his publisher.

Ghost Sonata by #johnpauljones arrives with Publisher @MSClassical @OPERAAmerica @ScottishOpera @DutchNatOpera pic.twitter.com/dGQAcAZkJq

— Gill Graham (@gg43) May 22, 2016

John Paul Jones wants it to tour the world

It doesn’t sound like “The Ghost Sonata” will just be staged in one city and that’s it. Jones told Tight But Loose that “it may be a combination of two or three opera houses that take it … what I’d like to do is stage half a dozen in one house and then go into another and hopefully it will go around the world.”