What the world needs now is love, sweet love. And the three brothers who make up Greta Van Fleet are making sure that there's plenty of that -- not just for some, but for everyone. Call the Kiszka siblings anything you want, but just don't call them retro. Even if the group’s galloping, Led Zeppelin-esque first single, “Highway Tune,” does have a strong whiff of 1970s arena rock dinosaur stomp, it's been racing up the Active Rock Radio tally -- hitting No. 3 this week -- keeping pace with bands like Highly Suspect and Royal Blood thanks to a fresh sound the brothers have been perfecting for half their lives.

"We had what I would call a vinyl playground growing up," explains singer Josh Kiszka, 21, about the immense record collection the kids got their hands on early and wore out thanks to their bass-playing dad. "We had these little record players and we would slow them down and speed them up and I was listening to people like Wilson Pickett, Joe Cocker, Sam & Dave, but we also listened to all kinds of other stuff, like John Denver."

The brothers from the small town of Frankenmuth, Michigan (pop. 5,131) -- guitarist Jake, also 21, bassist Sam,18, plus good friend drummer Danny Wagner, 18 -- have very quickly made a name for themselves with a debut EP released in April called Black Smoke Rising (Lava Records) that mixes wide-open Nixon-era bombast with wistfully flower power lyrics and revved guitars. And it's no surprise their vibe has such a Haight-Ashbury-circa-1968 feel (actual song title, "Flower Power"), since the boys didn't hear any contemporary music until they got to middle school. And even then they didn't really understand the hip-hop and dance pop their friends were into. "We were scratching our heads like, 'What does this offer?'' says Josh.

With 10 shows already sold out on their upcoming headlining tour kicking off at the Mercury Lounge in New York on Thursday (Aug. 24), more than 2.6 million streams of "Highway Tune" on Spotify to date and over 1.6 million YouTube views for the video, GVF is carving its own lane with snake-hipped songs they've been honing for most of their teenage years. Influenced by everyone from John Lee Hooker and Tchaikovsky to The Who, Jimi Hendrix, the Lord of the Rings books and, yes, a healthy dose of Led Zeppelin. The title track, "Safari Song" and "Flower Power" are the first shot in what Josh Kiszka tells Billboard is a deep songbook already packed with dozens of songs vying for space on their upcoming debut album.

Billboard spoke to Josh about the band's early days, the apocryphal-sounding tale of their agent signing them without ever seeing them live and a recent crowd-killing stint opening for English glam revivalists The Struts.

You said you couldn't really understand what your friends were listening to. But are there any bands from this era that you are into?

I really hope that we can make a bridge to some really good music. We still prefer all of the old stuff, but there’s a lot of great contemporary music, you kind of have to dig into it. Bands like the Fleet Foxes, Vance Joy’s “Riptide” and X Ambassadors... the Black Keys, Wolfmother.

Your bio says you’re also influenced by Tchaikovsky, Robert Frost, Lord of the Rings trilogy and Apocalypse Now. How so?

It’s like building a universe, you need manifestos and vision and so film and literature do that. Because then you’re dealing with morals and bringing philosophical questions into play. It’s a mind-expansive thing. My father had a big book collection and as we got older we got into it and we were reading [Friedrich] Nietzsche and [Jean-Paul] Sarte and comparing these theories and talking about stuff like [at the dinner table].

It sounds like you grew up in a kind of intellectual household?

I would say so. You could challenge each other and debate. There’s enough opinions at the Kiszka household... contemporary themes and ancient themes. Not a lot of TV watching. I can't stand the sound of television. My mother taught for a while and my father was a chemist, or more like an alchemist if you think about it.

You've been together for five years already. Do you remember the first songs you wrote or covered?

We started writing songs five years ago, but it's very different now, it's evolved. It's almost like it manifested, it's take on a maturity... the themes are a bit more adult. The overall quality and ability of each member and the sound have become tighter.

Let’s get the Zeppelin question out of the way: clearly you’ve listened to Robert Plant, but what you do is not an imitation by any means. How big an influence was that band?

He was a definite influence. We all appreciate Zeppelin and are grateful for what they did. That's the way I can get the most power out of my voice. Eventually it was that sort of thing, though it's not what I was going for. It's not unusual to share influences with someone you sound like. We were sitting around and saying 'you could sing like this,' but then it wouldn't have that same genuine feel to it. It would be like forcing some sound out of me that's not natural.

Between the pastoral lyrics, drums and your vocals, “Flower Power” does actually feel like it could be a Led Zeppelin 4 outtake.

That song is three years old now and it came about in one day. Jake had a riff on guitar and I came out and started humming and to me it offered a lot of that San Francisco scene, Haight-Ashbury vibe and it was written with a folk influence and a not to that era's sound.

Have you been surprised by how quickly “Highway Tune” has taken off?

Yes. I had no foresight as to what kind of momentum would shroud the whole thing. it garnered attention faster than any of us thought it would. I don't know why people are connecting to it, but when we write it's very genuine and when they listen it’s something they haven't heard in a long time. Or ever. The resounding appreciation is surreal and humbling.

It’s one thing to have brothers in a band, but twins as well? That just seems like it’s asking for trouble. Have you not been paying attention to Oasis and The Black Crowes?

Well, oddly enough we get along fairly well. It's about reminding yourself that you have to be logical. We learned from those lessons not to do things like that. If you're being mindful you know to be wary of dangerous things like that.

Is it true that Lava Records CEO Jason Flom heard your demos on a Friday and called your manager the next day to make an offer? And that the WME agency was so impressed by your music that they signed you without seeing you live? What sold them?

I'm not sure what sold him [Flom]. He must heave heard something that I hope had a genuineness to it, a power, a cohesiveness. I really don't know, but I'm glad he did. I'm proud of it and it's [the WME blind signing] a unique thing to have.

How was touring with the Struts earlier this year, seems like a match made in heaven? Did Danny and Sam really have to cancel their prom dates to go on tour?

They have an exotic, sexy, dark magical rock and roll glitter-ness about them. They have a masterful stage craft and that struck me immediately. They're tight and genuinely good people it was a lot of fun doing that. I didn’t know there would be anybody out there, and I worked 'is it a right match for this sound? Can we do anything with it? Can we make music with other people?' And then this was perfect! And yes, Dan and Sam had to cancel prom dates to go on that tour. They thought it was a fair trade off.

There’s a story floating around that on some of those dates the audience would cheer and clap as you were breaking down your gear. Is that true?

I think the audiences got it. The audience knew what they were seeing and there was that special movement of rock and roll coming through it. When people have access to all kinds of music at their fingertips, it's not about one genre. You can get caught up in what radio is pushing, but ultimately listeners are the people driving popular music.

There’s something fun about the fact that in these crazy times your songs aren’t about division and strife, but focus on love and unity.

Absolutely. That's a purposeful thing. Now and always there’s going to be conflict and probably the most logical and helpful thing we can be mindful about is to focus on the strength of humanity and not the flaws. Man is imperfect and will always be imperfect. Because we are humans and we are flawed there will always be some sort of strife and disagreement, but in that sense there’s also unity and people in the world cleaning up oceans and feeding the poor. In a busy world with everyone having busy lives and punching in and punching out, it’s hard to be mindful and hopefully the music that we’re making can be a sort of meditation and a light.