Inextricable from the music and choreography of Harry Potter and the Cursed Child is the music, and from the very start, director John Tiffany and movement director Steven Hoggett had the music of Imogen Heap in mind.

Heap had met Hoggett ten years earlier at Frantic Assembly, when he was directing a new play by Mark Ravenhill called pool (no water). “He wanted me to adapt music from an album I’d just released called Speak for Yourself,” she says. “It was a unique experience having him specifically ask to extend sections or change the timing of a piece.”

The Grammy-winning musician’s songs had been featured in films and on television, most notably the song “Hide and Seek,” from the Speak for Yourself album, which has been used in hundreds of iterations, from The O.C. to Saturday Night Live, to being sampled by Jason Derulo. Hoggett approached Heap about Cursed Child, and she was immediately happy to be involved.

Rather than asking Heap to compose an entirely new suite of music for the play, the production drew from her back catalog of instrumentals and the stems of songs. Stem files are a musical track split into four elements: for example, a drums stem, a bass line stem, a melody stem, and a vocal stem. For Harry Potter and the Cursed Child, Tiffany estimates that 80 percent was already existing material by Heap. “But they might be different versions that were never released, or stems that we and Gareth Fry could play around with. Then Imogen would build the tracks back up for us.”

Heap joined the rest of the team at the workshops with her computer, headphones, and various plug-ins. As she watched and worked, Hoggett, Tiffany, or music supervisor and arranger Martin Lowe would pepper her with ideas. “So I’d say, ‘I’ve got stems for that,’ or ‘I haven’t and need to make them.’ I’d email my assistant, Alexis Michallek, back in my studio in Havering. I was on chat with him all the time, asking for the stems and if he could send them this way or tempo map them to that,” says Heap.

“Sometimes I’d have thirty different individual tracks for each song, which would have the different drums, the different strings, all the vocals with which I’d pick and choose what I wanted.”

Heap also worked with sound designer Gareth Fry and his team of Peter Malkin and music editor Phij Adams. Heap and Fry could riff off each other, sometimes working with a sound effect, sometimes working with a music cue. For one scene transition, Fry chose to use the sound of a foghorn. “But he took it to the key of my music from the previous scene,” she remembers. “And then I took his sound and brought it into the music.” When music needed to match the sound effect of the Hogwarts Express gaining speed along its tracks, Heap took Fry’s work and mapped the drums in her music to follow the tempo of the train. It can be challenging to discern where a sound effect ends and music begins, or vice versa.

Hoggett and Heap's choices for the music often and unwittingly matched the original theme or lyrics of the piece. “For instance, the music behind the scene with Moaning Myrtle is from an original song called ‘Little Bird,’ where the lyric goes, ‘Little bird, little bird, what do you hear?’” says Heap. “And Moaning Myrtle hears everything in the pipes in the toilets.” Another is the use of her song “Aha!” behind the scene of Albus and Scorpius atop the Hogwarts Express, where they’re caught by the Trolley Witch. “That’s about catching somebody out when they do something that they say they won’t do,” she adds. Similarly “Lifeline”—the song chosen for the transitional scene across Albus’s first three years at Hogwarts—was selected for its rhythm and texture, not its lyrics, and yet it’s “about life before and after a moment in your life,” says Heap.

Rhythm and texture were key in finding the right piece of music for the Wand Dance, Heap’s “Cycle Song.” “I like the choice of the time signature of the song from Steven’s perspective,” says Heap. “The students are trying to figure out how to learn wand moves. And the song is a bit awkward—it’s not quite in time—so it was really fun to play with.”

This is an extract from Harry Potter and the Cursed Child: The Journey.

Harry Potter and the Cursed Child: The Journey, by Jody Revenson, publishes on 31 October, 2019 in the UK and 5 November, 2019 in the US.

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