He launched a music career that earned Grammys and commodified cool. But along the way, Lenny Kravitz has kept one ear cocked to the melody of interior design — the architecture, the palettes and grace of beautiful things set in beautiful places.

The platinum-selling musician started by designing his own spaces in the 1990s. Then he helped friends do theirs. And by the time his guitar grooves were already a radio staple, nearly a decade ago, the rocker was launching Kravitz Design, a New York-based boutique firm whose imprint now extends from Kravitz’s rustic farmhouse in Brazil to a tony chateau in Paris to the soaring landscape of condos and hotels in South Florida.

He calls the Kravitz treatment “soulfully elegant,” the product of a New York upbringing, a global itinerary and a fluency in hotel living.

Most recently, Kravitz delivered his stylized aesthetic to the just-opened SLS Hotel in Miami Beach and Paramount Bay in Miami, a waterside condo tower he now calls home.

“Design is something that burns deep within me,” Kravitz, 48, says in a phone interview from Paris. “I knew when I started, I didn’t want this to be a vanity project but something I was intimately involved in, something that grew slow and organically.”

Last year, his vision was unveiled at the 47-floor Paramount Bay. He was chosen for his design sensibilities and deep Miami roots, and his use of rich hues and finishes blends Miami’s urban energy with his own cosmopolitan style. The translation: sexy public spaces and model units awash in exotic woods, textures and earth tones including a lobby with slabs of sleek marble and indoor gardens.

“It was really about capturing the Miami lifestyle. I have been here off and on for a long time. My mother’s family is from Bahamas, and I have spent a lot of time in the city,” Kravitz says.

“The idea was to create spaces that bring people together, that are open for creativity, conducive to sharing and conversation. I wanted a space that is beautiful but also someplace you can really live in.”

His firm, opened in a SoHo studio in 2003, was also tapped to partner with Philippe Starck to design the tower penthouse and villa penthouse for the SLS Hotel, a luxury property carved from the aging bones of the Ritz Plaza, an Art Deco hotel built in 1939. His vision there was that of a seasoned traveler who has lived large over the decades — much like the Ritz itself.

“I remember seeing this Art Deco building and thinking it would make the most incredible project. The key is to retain the original feel, paying a lot of respect to that era, to the Art Deco-ness of it,” he says.

“I want the rooms to look like a world traveled by plane, car or by boat, like a traveler who has collected things along the way, and I am working with local artisans to make it feel that way.”

As with other projects, Kravitz brings a design sense imbued by a music career that has exposed him to an array of cultures and experiences.

“Lenny is a weapon of massive construction. He is an explosion of all talents, an unlimited boiling bucket of culture, a daily firework, a tireless explorer,” said Starck, who was wowed by Kravitz’s Parisian digs on a visit about three years ago. “Lenny is incredibly alive. Lenny is a friend.”

The two projects are not Kravitz’s first foray into Miami’s eclectic design world: He designed the two-story penthouse recording studio at the Setai and the Florida Room at the Delano Hotel.

The goal has always been the same: an inspired and welcoming environment.

“I like to think my style is soulful elegance. It’s one thing to be sophisticated, but another to be that and casual and comfortable,” he explains. “I lean towards organic finishes, stones, shags, glass, cork. I like high-low and slick clean lines next to organic.”

Kravitz was recently hired to re-imagine the private residence of a wealthy Parisian entrepreneur he describes as “somebody who works hard and wants a place he doesn’t have to leave; he wants the place to feel precious and opulent and young and fun and accessible.”

He launched his firm almost 10 years ago, but it was a lifetime in the making. The world was introduced to Kravitz — the son of actress Roxie Roker and producer Sy Kravitz — as an icon of music and style. But all the while, he was making himself into a designer.

“As a child, it was really important to me how my room looked. When I got my own record deal and I began to get my own spaces, I really got into design and making a place with a certain vibe. I found myself getting pieces made that I could not find or afford.”

Before long, he had designed his bachelor pads. In the portfolio: a 2-century-old Creole cottage in New Orleans’ French Quarter, a majestic townhouse in Paris filled with contemporary art and a 1,000-acre organic farm in Brazil.

“I was constantly making changes to my spaces based on my moods, like three times in five years, and I finally said to myself: This is ridiculous, I need to have an outlet where I can design,” he says.

The brand extends beyond designing spaces. Kravitz has contributed chandeliers to Swarovski’s Crystal Palace Collection, partnered with Flavor Paper for a collection of hand-screened wallpapers and joined Italian manufacturer LEA Ceramiche to produce Goccia, a collection of three-dimensional wall tiles inspired by water and waves.

“I wanted to create a design element that provides texture and movement to the living environment,” he says.

Kravitz also reinterpreted the Mademoiselle chair designed by Starck for Kartell, unveiling his six versions at the Milan Design Fair this spring.

Now — as he tours in support of his ninth studio album, Black and White America — Kravitz is in discussions to launch a lifestyle brand that would include furniture, décor, luggage, even some clothing, a la Ralph Lauren. He wants it to be a mix of luxury and affordable design.

“People understand the idea of living in a chateau in Paris or vacation on a yacht. They understand that as good living. But there is also beauty in the favelas of Brazil, and I want the brand to reflect that,” he says. “Everybody should have access to good design.”