“You were obviously having so much fun in this empty hotel,” said Jagger, 77, referring to the use of the currently unoccupied Claridge’s hotel in London as a set for Mescal’s seemingly drunken shenanigans. “I thought you were going to kill yourself when you jumped down the stairwell.”

“So did I,” confessed Mescal, 24.

The “Scarlet” video is a bit like a more happy-go-lucky — or happy-go-drunky — version of “The Shining,” with Mescal left to his own devices in Claridge’s to leave lonely voice messages for the title character, drink, pull his bow tie loose, dance, drink some more, draw on the mirror with lipstick, dance and drink further still, and finally collapse with a crash on the lobby floor.

“Due to the pandemic and hotels being closed, the production team could kind of aim big in terms of the location,” Mescal says, and “the staff of Claridge’s were amazing.” Room rates will no doubt go up when quarantining is over and Stones- or Mescal-loving tourists ask for the “drunk-dialing your ex suite.”

“What do you think of the video itself?” Mescal asked at the beginning of the convo with Jagger. “And if it’s mean things, I’ll just shut the laptop briefly and then open it back up again.” Jagger, obviously, signaled his approval.

Mescal and Jagger interviewed each other for a few minutes, with the actor asking the rocker (or, actually, rocker-actor) why “Scarlet” sat on the shelf for so long. The track is from an upcoming box set celebrating the Stones’ 1973 album “Goats Head Soup,” and is one of three completely unreleased compositions in the collection. It’s notable for subbing out some members of the Stones for Jimmy Page as a second guitarist to Keith Richards, and including Rick Grech on bass, in what was clearly intended as a demo.

“I mean, remember doing it in many versions,” Jagger said. “I remember doing it with lots of different people. (But) I don’t remember doing this. And I talked to Jimmy Page and he said, ‘Oh yeah, I remember doing it. We sat in Ronnie Wood’s recording basement, and it was these people…’ He remembered everything. I remember being there, but that’s all.”

Jagger added, as explanation for its nearly 50-year shelving, “It wasn’t really a Rolling Stones record.”

Mescal asked how the lockdown has been for the Stones.

“I think it’s not been too bad, because we were sort of hallway through an album,” Jagger replied,  and we released a song called ‘Ghost Town’ that was one of the songs that we were working on that we finished off. And now I’m in the middle of doing vocals on some of the other ones, trying to finish those off, and then write some new ones as well. So it’s not so bad for musicians.”

Mescal responded, “I envy the kind of process that writers have, or maybe musicians. Because for you I imagine it’s got two kind of edges — it’s the writing side and then the live gig side — and you’ve still got one side that you can work on. Whereas I think that our job is totally related to an audience, be that on screen or on stage.”

The conversation included a brief bit of banter about current musical inclinations, with the Stones’ frontman noting that he had recently done a playlist which included a lot of African music, heavy on the Somalian side, along with listening to “lots of current pop music to know what’s going on now.” Asked about his music tastes, Mescal did not butter up his host by citing the Stones, but answered instead: “Predominantly, sad music is my go-to. Sad indie music would be my general taste.”

“How much do you think you’re like your character Connell in the TV show?” Jagger asked.

“Like, internally, definitely quite different,” Mescal answered. “I think on the surface, in terms of like his trajectory through secondary school and college, probably similar. But thankfully I’m a little bit better at maybe articulating how I feel about a situation that I’m in, which I think Connell is incapable of doing. He can’t do it. He just simply can’t say how he feels at any kind of critical moment. Which is fun to play, but thankfully I don’t walk around my life permanently indecisive emotionally.”

Given his ruinous attitude toward his own health and the hotel’s in the “Scarlet” clip, there’s little danger of anyone mistaking Mescal riotousness for reticence at the moment.