GWEN IFILL: Finally tonight: a genre-bending musical look into the mind of Albert Einstein.

Jeffrey Brown tells the story.

JEFFREY BROWN: It's called "Einstein on the Beach." And it's now receiving a rare revival and a world tour, most recently at the Brooklyn Academy of Music.

But there's no beach, and it's not about Einstein, at least in any traditional storytelling sense. It's also called an opera, though, according to its composer, Philip Glass, that too is up for grabs.

PHILIP GLASS, Composer: You can call "Einstein" anything you want to, but the only place it fit was in an opera house.

JEFFREY BROWN: So, therefore, it's an opera?

PHILIP GLASS: Well, you know, that's not a bad definition.

And when I look at the work I have done and people say, which are operas and which aren't, I say, well, the ones we do in opera houses are operas. Good definition.

JEFFREY BROWN: So, what is "Einstein on the Beach"? It had its premiere in Europe in 1976 and then in two sold-out performances at the Metropolitan Opera in New York.

It mixes experimental forms of music, swooping arpeggios that repeat and vary, dance, theater, and contemporary art into a long—and I mean long—nearly five hours—event. It's abstract without a story to follow, more a collage of sound, movement and images, a musician in an Einstein wig playing the violin, singers chanting numbers, clocks moving forward and backwards.

PHILIP GLASS: The amazing thing is that what you see or almost everything you see is things that Einstein talked about. When he was talking about his theories, he talked about space and time, he talked about trains moving. He talked about clocks.

If you look at the stage, you're looking at the furniture of his imagination.

JEFFREY BROWN: Thirty-six years ago, "Einstein" thrilled many viewers and critics and infuriated others. No one had seen anything quite like it.

Its admirers hailed it for tearing down borders between different arts in ways that are still with us today. But for Glass and his collaborator, director Robert Wilson, captured in a 1976 photograph by Robert Mapplethorpe, it was the culmination of years of working out ideas and working with other artists.

PHILIP GLASS: We were part of a generation of people who were furiously experimenting with collaboration. It was a great thing of that generation, and still going on today.

What we were doing was putting together what he knew and what I knew into something that would be new. But we weren't thinking of a seismographic change of the art world at all. We were trying to get through the piece. We were trying to put it together.

JEFFREY BROWN: In fact, "Einstein on the Beach" began with a series of drawings done by Wilson, each imagining a scene or idea they had discussed.

So he did the drawings.

PHILIP GLASS: Yes.

JEFFREY BROWN: And you looked at the drawings.

(CROSSTALK)

PHILIP GLASS: And it was as simple at that.

JEFFREY BROWN: As simple as that?

PHILIP GLASS: Yes. It really was.

JEFFREY BROWN: Philip Glass grew up in Baltimore, where his father owned a record store with a wide-ranging collection. By age 15, young Philip was the unpaid classical music buyer for the store, getting a hands-on education.

PHILIP GLASS: My father took a liking to modern music, because he found he had records in the store that nobody would listen to. So, he would take them home to listen to them. He didn't know anything at all about music really. He was a—ended up in this odd business.

JEFFREY BROWN: Right.

PHILIP GLASS: But he was a very smart fellow and learned a lot along the way.

And at one point, he took the records home and he said, well, if they don't—I have to listen to find out what's wrong with them. And if I find out—if I know what's wrong with them, I won't buy the bad ones anymore.

JEFFREY BROWN: So, this was contemporary classical music?

PHILIP GLASS: It was Shostakovich and Bartok and we would listen to it. And after a while, we—and I was his companion in listening.

JEFFREY BROWN: He went on to study at Juilliard and also in Europe and also worked with non-Western musicians, such as sitar virtuoso and composer Ravi Shankar, before helping pioneer a musical style known as minimalism.

Glass prefers to describe himself as a composer of—quote—"music with repetitive structures." And that's what he's become famous for, indeed perhaps the most famous contemporary composer, captured in a well-known portrait by artist Chuck Close.

But it wasn't until his 40s, Glass says, that he was able to make a living at music and quit his day of driving cabs in New York. "Einstein on the Beach' first made his name, but also left him broke.

PHILIP GLASS: What we didn't know—and this is because our naivete was that we thought, since we had sold out the house, we didn't—couldn't possibly have lost money. What we didn't understand is that operas always lose money when they sell out of the house.

JEFFREY BROWN: You just didn't know.

PHILIP GLASS: We didn't know. We never expected to make a living at it, to be truthful.

JEFFREY BROWN: You didn't?

PHILIP GLASS: No.

JEFFREY BROWN: So it just seemed impossible?

PHILIP GLASS: Well, it seemed unlikely.

JEFFREY BROWN: Unlikely perhaps, but many years later and after numerous operas, symphonies and Oscar-nominated film scores such as "The Hours," Glass is still thriving.

PHILIP GLASS: I'm delighted to be involved with "Einstein" again, to see the energy of it and how it connects with the younger performers. It's inspiring, actually. They're finding things in it in and ways of performing that we didn't know. It gives you a lot of hope for the future.

JEFFREY BROWN: In his 75th year, Philip Glass is being honored and celebrated in concerts around the world, and "Einstein on the Beach" is back to confound, challenge and engage audiences.

GWEN IFILL: The "Einstein on the Beach" tour continues this coming weekend in Berkeley, California.