Christopher Nolan says Travis Scott's track 'The Plan' was the ''final piece'' of the 'Tenet' puzzle.

The 29-year-old star has recorded the lead song for the movie's soundtrack, and the film's director has opened up on how significant it really is.

He told GQ magazine: ''His voice became the final piece of a yearlong puzzle.

''His insights into the musical and narrative mechanism [composer] Ludwig Goransson and I were building were immediate, insightful, and profound.''

Although Scott hasn't revealed any secrets about the highly anticipated blockbuster, he promised fans wouldn't be disappointed.

He added: ''I can't even explain it. You literally just have to watch it. It's very fire.''

'The Plan' will be released on Friday (21.08.20), ahead of the film premiering on August 26, after being delayed due to the impact of the coronavirus pandemic.

Meanwhile, filmmaker Nolan previously warned editor Jennifer Lame that the spy thriller could be one of the most challenging movies to edit due to the complicated nature of the plot.

He explained: ''Working for the first time with editor Jen Lame was a real pleasure.

''I joked with her when she first came on that this might be the hardest movie any editor has ever had to cut - and I'm not sure she would dispute that right now.

''Working out all the aspects of portraying time running in different directions meant going beyond what was down on the page, as the execution lay with a successful translation of the visual.''

Nolan hired Lame after seeing her work on projects such as 'Manchester by the Sea' and 'Marriage Story'.

The 'Inception' director said: ''For me, hiring is about looking at the work people have done in the past, but not necessarily in relation to what you're looking to do.

''I look for excellence and judgement. When meeting, it's more about discovering if there's a common creative language, which is exactly what turned out to be the case.''