Over a four-decade career as lead singer for Def Leppard, Joe Elliott has sung about sugar, passion killers, hypnosis, “magical mysteria,” pyromania, being brought to his knees by love and riding on a nightmare machine.

But until recently, Elliott and band, which formed in Sheffield, England, in the late ’70s, didn’t think much of music streaming.

Long after holdouts Led Zeppelin, the Beatles, Metallica and AC/DC remastered and unlocked their music, Def Leppard steadfastly refused to cave until it was able to negotiate what the band considered equitable compensation from Universal Music.

The two sealed a deal late last year, and soon after, the band’s music shot to the top of the rock charts as though this were 1983. Since then, sticky-sweet rock songs such as “Rock of Ages,” “Photograph” and “Pour Some Sugar on Me” — which remain staples on heartland FM rock stations — have earned millions of streams.

It’s a busy summer for Elliott, whose band is currently on tour with Journey. The following is an edited transcript of the conversation.

Q: You were one of the last of the major rock bands to make your music available to streaming services. What took so long?

A: Because we signed a deal in ’79, there was no digital (agreement) in place, because there was no digital. Our contract with (Universal) was purely for the physical. When we did kind of iron out a deal for (streaming) in about 2010, it got torn from underneath us by previous regimes — let’s put it that way. That put us in a bit of a bad mood. We said, “OK, well, we’ll just do our own thing.”

Q: When your original albums did arrive on streaming platforms, they shot to the top of the rock charts. Were you heartened by the reception?

A: I was flattered, humbled, heartened, excited — every positive emotion you can think of. And it’s so instant. Back in the day, you’d put your record out and then it’s like, “What’s happening?” You’d be waiting for these telexes to come out of the machine the size of 10 washing machines. ‘You sold this much ...’

Q: I went back and checked how we reviewed your early concerts. They weren’t kind.

A: Oh, yeah, we were never press darlings — never will be ... . If you weren’t Lou Reed or Loudon Wainwright or Elvis Costello, you were just an idiot — just this brainless buffoon rock ’n’ roll nonsense.

Q: And at the time, punk was being praised by the critics.

A: That was the ironic thing. We were being told of all these bad reviews, and all these critics were raving about punk. We’re going, “Dude, we’re from England. We were there when punk happened. You’re five years behind the ... eight-ball here. You are missing the point.”

Q: Well, there was Black Flag, the Germs and hardcore.

A: It was hardcore, but you called it punk. If you want my honest opinion, I don’t think you can be punk unless you’re from the U.K. I think you can like it and want to make punk music, like Joan Jett does or Green Day. I think you can be generally great bands, but I think that the whole punk thing was born — it’s like the blues. You can’t really be a bluesman if you’re English.