Cynthia Erivo and Ariana Grande reunite on stage

Two actresses who are good friends sang together on a big stage.

Their names are Cynthia Erivo and Ariana Grande.

Cynthia called Ariana her 'sweet sister' and her favorite person to sing with.

They sang two special songs that mean a lot to them.

One song is called 'For Good' and the other is 'Get Happy/Happy Days Are Here Again'.

These songs come from a movie called 'Wicked'.

In the movie, Ariana plays a character named Glinda and Cynthia plays Elphaba.

Cynthia shared videos of their singing on Instagram.

She said she will never forget that night.

She thanked Ariana for inviting her to sing together.

They both love music and their fans very much.