Why does Pharrell's biopic sidestep Blurred Lines?

Piece By Piece, the new documentary about musician Pharrell Williams, is unusual in many respects - not least because it is entirely animated with Lego.

Critics have welcomed the film's unique visual style, calling it "disarmingly joyous" and "oddly charming" - but they've also questioned one of the film's big omissions.

Robin Thicke's Blurred Lines, which Williams co-wrote, is heard briefly on the soundtrack, without referencing the song's infamous plagiarism trial, which left the musician owing $5m to the estate of Marvin Gaye.

Speaking to the BBC, director Morgan Neville said he had wanted to address the controversy, but the sequence ultimately derailed the story he was trying to tell.

"I definitely thought about it. I even interviewed Robin Thicke," he said. "And as a documentary filmmaker, I'm obsessed with copyright law.

"But every time I looked at trying to work it in, a scene about copyright law, it felt like it belonged in a different movie."

The Blurred Lines trial was hugely consequential for the music industry, after a jury ruled that Williams and Thicke had copied the sound and "feel" of Marvin Gaye's Got To Give It Up - rather than plagiarising a specific melody.

The general consensus among music lawyers and songwriters is that the verdict failed to distinguish between influence and theft.

It has now become common practice for musicians to assign a share of their royalties to songs that directly inspired them.

"My take on the Blurred Lines case is that it's one of the worst judicial decisions about creativity in history," Neville told the BBC. "I think Pharrell was in the right on it, and I think most creatives agree with him."

Ultimately, that led to him omitting the story from the documentary.

"It's not like Pharrell learned a big lesson from the case. I don't know if it actually changed him in any way, which is what I'm looking for, when I'm looking at a story."

Williams has been contacted for comment.

Neville previously won an Oscar for 20 Feet From Stardom - a documentary about the forgotten lives of backing singers who feature on some of rock's biggest songs.

His other documentary subjects include Keith Richards, Brian Wilson, Johnny Cash and, as a producer, Taylor Swift.

With Piece By Piece hitting cinemas this month, Neville told us about the film's unexpected genesis, how he convinced Lego to come on board, and the stars who had notes about their Lego minifigures.

In the film, you dramatise the moment Pharrell asked you to make the film in Lego, and your response is “Lego? Seriously?” How true to life was that?

The main difference is that when Pharrell said “Lego movie”, I thought, “Hell, yeah!”

I knew it was a crazy idea, but an exciting idea. I think it took me five minutes to fully buy into it.

Can you break it down for me? What was Pharrell’s pitch?

He basically said, "People have always wanted me to tell my story, and I've never been that interested, but I love your films, and I had the idea that you could make a documentary about me, and when you were done with it, you could throw away the visuals and do it again as Lego."

That’s almost exactly what he said to me – but beyond that, he had no sense of what that meant, or what his story was. So I really had to think, what does that mean?

And one thing I instantly I realised is that it's not just about taking the real-life documentary footage and making it Lego. It's using what animation can do, which is time travel and go to outer space and all kinds of things that you can't normally do in a documentary.

How quickly did it go from a crazy idea to reality?

It took us about a year from when we first met to starting production, because we had to meet with Lego and tell them about it.

How did the conversation with Lego go?

I said, "Look, it's not a G-rated movie, but I get that it can't be R-rated [either]. It's something that has to have a little edge, and it's going to get into questions of race and other things".

And Lego, to their complete credit, said, "Those are conversations that are good for us to have."

They knew it would push them, but in ways that they thought were good.

But they didn’t fund it, they don't own it, they're just partners.

What was the moment you knew it would work?

Well, we had to figure out how to get somebody to pay for it, so we did a 90 second proof of concept.

I interviewed Pharrell, and I cut together a scene of him listening to Stevie Wonder as a boy, on his parents' stereo – and his synaesthesia kicks in. Suddenly there's lots of colour and you can almost see what's going on in his mind. That convinced me it would work.

I love the way you visualise Pharrell’s beats as Lego sculptures, each with its own unique shape. It really helps illustrate the abstract concept of songwriting.

Do you know, what was interesting about the beats? Pharrell, in his mind, can tell you the colour and the shape of every beat he's made. So for each of those Lego pieces, we actually worked with Pharrell to make sure they looked like what he saw in his head.

When you interviewed other people for the film – Missy Elliot, Jay-Z, Snoop Dogg – did you tell them it was going to be rendered in Lego?

We didn’t, partly because we filmed those interviews five years ago and we wanted to keep it on the down low.

Then, cut to a couple years later, and I started sending out 3D renders of their characters, like, "Here you go. This is what you're gonna look like".

It was a bit of a roll of the dice, but everyone was really excited about it.

Did anyone ask for changes?

Missy had a comment on her earrings, so one of the few bespoke [Lego] pieces that we made for the film were Missy's earrings.

The Lego characters have a limited range of facial expressions. Did that pose a problem?

The face stuff was the thing I was most worried about, because when you have close up shots of a Lego minifig crying, is that going to be emotional? I didn't know.

But there were a few animators on our team who were really good at facial animation, and we gave them the most emotional scenes, the close-up scenes. And oftentimes, if something wasn't quite right, we would send them videos.

Somewhere in the world, there are a whole lot of clips me and Pharrell making very strange faces!

The arc of the film is Pharrell re-discovering his muse after a period where he gets lost, creatively. Why did you focus on that aspect of his story?

Without a doubt, the film reflects a lot of questions I've had about my own career.

To me, the story about this black nerd from the projects of Virginia who sees the world differently... and it makes him an outcast for a long time. Then he finds a fellow outcast in Chad Hugo [Williams' co-writer in The Neptunes] and they start making music.

But their beats were just too weird for people. The signature Neptunes sound was very unorthodox. Nobody got it until everybody got it. Then you end up in this hall of mirrors – where the thing that makes you different becomes the sound of the mainstream. When that happens, how do you stay true to yourself?

Your film comes out at the same time as the Robbie Williams biopic Better Man, where he's played by a CGI monkey. Do you think music biopics had become too formulaic?

I do. There's so many tropes of music films, and I think we need to do more to help people identify with the people and with their characters.

I haven’t seen Better Man yet but the idea's perfect because, in a way, Robbie Williams is the performing monkey. He wants the attention. He's always lived that life.

And Pharrell is the Wizard of Oz. He's like, "I want to be the guy behind the curtain."