On what turned out to be their last album together, Simon and Garfunkel created what some regard as a masterpiece.

The album contains some iconic songs, not least the title track, “Bridge Over Troubled Water.” Some of these are lodged in my marrow, songs that feel like I’ve known them forever that recall distant times, places, and feelings.

“So Long, Frank Lloyd Wright” is not one of them.

It’s the strangest track on the album, and I’ve known it for less than half the time I’ve known their more famous songs. It’s a song about an architect that doesn’t seem to be that at all. It has a bossanova rhythm and a sparse arrangement of classical guitar and congas, with strings freely doing their thing in and out of the track whenever they feel like popping up.

And yet, its light, jazzy feel gets under your skin and makes you feel free and easy. It’s one of the many examples of Simon’s ability to make a very complex song and arrangement seem simple.

Art Garfunkel had studied architecture, and he suggested his partner should write a song about Frank Lloyd Wright. What Simon actually did was write a sad and poignant break-up song about his musical partner that sounded as bright as a sunny spring day.

The “so long” from the title embodies Simon saying goodbye to Garfunkel. He’s cryptically telling his partner that they are splitting up. With that in mind, suddenly the words are heartbreaking:

I can’t believe your song is gone so soon
I barely learned the tune 

It’s quite a tangled state of affairs. The singer is oblivious to the fact that he’s singing about himself, and also singing about the fact that soon they won’t be a duo any longer.

I’ll remember Frank Lloyd Wright
All of the nights we’d harmonize till dawn
I never laughed so long
So long

Lines like these seem almost callous, especially with the clever double meaning of “so long.”

Eventually, Simon gets to the only lines he sings in the whole song:

Architects may come and architects may go
And never change your point of view
When I run dry
I’ll stop a while and think of you

It seems like an acknowledgement of what Garfunkel means to him, but it’s also a statement: he’ll use the breakup for inspiration in the years to come. And as if to foreshadow how long the ache will last, at the end of the song – unaware that goodbye is on the horizon – Garfunkel repeatedly sings:

So long

He sings it so many times that producer Roy Halee eventually shouts:

So long already, Artie

And that exasperated outburst is pleasingly left intact on the final track.

A slightly happier ending is that Art Garfunkel eventually went back to the song, used and performed it, and overcame its double meaning because he found it so much fun to sing.

This being a Paul Simon song, the fiendishly clever lyrical puzzle is underpinned by lightness. There’s a flute solo that makes you feel like you’re skipping under sun-dappled trees. The song makes you feel like you’ve known it forever, as intimately as one of their all-time classics.

Simon and Garfunkel songs often feel like I’ve known them forever. They recall distant times, places, and feelings. And now, thanks to the power of Paul Simon’s masterful songwriting, “So Long, Frank Lloyd Wright” is one of them.