Given John Lydon’s strained relationship with the recording industry, it seems fitting that the reunion of his post-Sex Pistols band Public Image Ltd. has been funded not by a record label, but rather a butter company. In 2008, the British butter maker Country Life recruited Lydon for an unlikely TV commercial, compensating him generously.

“I thought it was the most anarchistic thing I’d ever heard,” Lydon recalls. “Johnny Rotten selling butter! If you can’t see the fun in that, then you’re dead.”

The commercial dressed the orange-haired singer in a tweed suit and pit him against the British countryside, where he was chased by cows. Though punk idealists didn’t find much humor in one of the genre’s seminal figures becoming a corporate spokesman, Lydon justified the commercial by using his paycheck to jump-start Public Image Ltd. (PiL).

“It was something I had been wanting to do for a long, long time, but the money was never there,” Lydon says of reuniting PiL, which had remained dormant since Virgin Records dropped the group in 1992. “There was no money or interest from the record company, so I did other projects. They were all to get me the money so I could reform PiL. That butter campaign finally gave me the money to do that. I am the kind of person who really does put his money where his mouth is.”

Lydon believes that record labels have a systematic bias against any music too far outside the norm. “When you present your new product to the record company and it doesn’t sound like anything they’ve ever heard before, they balk at the prospect,” he says. “I’ve been criticizing record companies for 30 years. They were always 10 steps behind, and it showed.”

In truth, though, PiL was never an easy sell for record companies. Their first albums, recorded after the Sex Pistols’ 1978 breakup, were dense and atonal, building towers of noise over a shaky foundation of thick dub reggae. Even as their sound grew cleaner and dancier throughout the ’80s, in part because of constant lineup changes, Lydon’s edgy, animalistic wail kept their most accessible pop songs from climbing too high on the charts.

“I view my voice as an instrument,” Lydon says of the odd delivery he honed with PiL. “Language is the greatest human achievement, but language is still very limited, I discovered. There are certain emotions, like grief, that language really can’t express. I realized that so much of what we do as human beings is imitating the sounds of birds and nature and insects. That’s why I host nature programs. I’m captivated by that form of expression. When I look at a chimpanzee, I know he wants to talk to me.”

Where Lydon’s songs for the Sex Pistols were written around sweeping, often fiercely confrontational statements, his songs with PiL were markedly more personal.

“I went as far as I could songwriting with the Pistols,” Lydon says. “With the Pistols’ song ‘Pretty Vacant,’ I love the irony of that, because I’m not pretty, and I’m not vacant—I’m from small beginnings, and it’s extremely gratifying to come from that. But I’m much more interested in true emotions. I love songs to be truthful and genuine and honest, and not just manufactured. My songs are from the heart and soul. They’re about the deaths of people I love, or their rise or their successes. They’re about what impresses me in other people, and what depresses me about other people. But they’re mostly analytical. That’s the constant string that runs through Public Image Ltd.: This is a human being analyzing human beings.”

With that mentality, songs still come easily to Lydon, who has stockpiled plenty since PiL’s hiatus. “I can never be short of things to write about,” he says. “Every single human being you meet for the first time is an inspiration.” His challenge, then, is finding the money to record them, something he hopes to do through the band’s reunion tours.

“It will be better than all the others,” Lydon promises of the next PiL album, whenever it should arrive. “I wouldn’t put out a record if I thought it was inferior. I believe in every song I write.”

Public Image Ltd. plays the Pabst Theater on Friday, April 30, at 8 p.m.