On 29 April 2017 Katy Perry "was emotionally transformed forever" after seeing Dear Evan Hansen on Broadway. The Tony award-winning best musical had a profound effect on Perry when she was facing mental health issues. "In my own life, I've struggled with depression, and like so many, always feeling alone in the battle of wanting to belong," the singer revealed on a recent Instagram post.

One particular song had a significant impact on Katy Perry, "Waving Through A Window". The song was performed by Ben Platt in the original Broadway show. Perry connected with the poignant message of the song. "Waving Through A Window" deals with the feeling of being on the outside and being powerless. Fans of the show, including Perry, relate to the lyrics "One the outside always looking in / Will I ever be more than I've always been? / 'Cause I'm tap, tap, tappin' on the glass / I'm waving through a window / I try to speak but nobody can hear, so I wait around for an answer to appear."

Katy Perry jumped at the chance to re-record the song when approached by the show's creators Benj Pasek and Justin Paul. She re-recorded the song to help the launch of the national tour of Dear Evan Hansen in the U.S. However, Perry explained it meant much more to her than a promotional cover. She hopes "to continue the conversation on mental health and all its complexities" through her re-record.

Listen to Katy Perry's version of the musical number below.

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Dear Evan Hansen creators Pasek and Paul launched a new deluxe album of the musical which includes unreleased songs, demos and acoustic versions. Watch the full video below.

The hit show will be coming to London's Noel Coward Theatre in November 2019. Tickets are not on sale yet, however eager fans can sign-up for pre-sale via dearevanhansen.com/london.