There are dozens of these "lotsa different performers in their homes" videos, many done for good causes. This one features 23 West End actresses who played either Elphaba or Glinda in the musical Wicked, raising their fine voices in the best song from that show.
The good cause is The Make A Difference Trust, which helps those "experiencing hardship because of the ongoing coronavirus crisis." It's like the British version of The Actors Fund here. This song has probably never been sung better — or with more genuine meaning…