Cynthia Erivo is a multi-award winning singer and actor who has starred in hit Broadway shows as well as taking on high-profile screen roles, so she is perfectly qualified to judge the musicals themed episode.
She'll be filling in for Revel Horwood who is now in isolation - a blow to the West End theatre pro who usually sees the musicals-inspired show as a series highlight.
Erivo has starred in a Broadway revival of The Colour Purple, the Sister Act UK Tour and The Umbrellas of Cherbourg.
She played the lead role of Aretha Franklin in the third series of Genius, the title role in acclaimed biopic Harriet, is currently filming for the new Luther movie and will star as Elphaba in the forthcoming film adaptation of the musical Wicked.
Her trophy cabinet includes a Daytime Emmy Award, Grammy Award and Tony Award, and she has been nominated for two Academy Awards.
Erivo said: "I’m so delighted to be joining the Strictly judging panel for musicals week. Musicals have a unique place in my heart, it’s such a special way of connecting all art and making it one.
"I’m excited to bring my experience to the show and I can’t wait to see what the couples have in store this weekend."
She will sit alongside Motsi Mabuse, head judge Shirley Ballas, and Anton Du Beke with Revel Horwood expected to return next week.
This weekend's performances will include a Frozen-inspired Quickstep from Rose Ayling-Ellis and Giovanni Pernice, a couple's choice routine from Tom Fletcher and Amy Dowden themed on Les Miserables, and a Mary Poppins-inspired Viennese Walts from John Whaite and Johannes Radebe.
Revel Horwood is not the only Strictly star to have been hit by coronavirus this series - Fletcher missed a week early in the series after a positive COVID test, and Judi Love was voted out the week after she returned.
Watch: Who is I'm A Celeb's Dame Arlene Phillips?