Tracee Ellis Ross joins mom Diana Ross on stage for surprise song

During her final show last week at The Venetian Theater in Las Vegas, Diana Ross surprised her daughter Tracee Ellis Ross by inviting her onstage to sing a rendition of Billie Holiday's "Lady Sings the Blues."

The nervous -- and funny -- Black-ish star held her own as she sang a few bars with her mom at her side, occasionally reminding her daughter of the lyrics.

Ellis Ross took to Facebook on Sunday to describe the experience and share a video of the performance. "Last week, in Vegas, my mom, out of nowhere, stopped her show and asked me to come onstage and sing. I think the last time my mom asked me to sing I was 5 or 6 years old," she wrote. "I swear at first I thought she said Evan (my brother, a singer, who was also there). But then I realized she said my name, and before I could think, I was walking toward the stage!

"Now, I'm not afraid of much. I used to be afraid of everything. I was shy as a child. Probably tough to believe but it's true. I still get nervous all the time, but I never let it stop me and I'm certainly not afraid of performing. But, somehow, by the time I stepped onto the stage it was as if I was 6 years old again! There's something about singing..... It's no joke trying to do that as the child of DIANA ROSS, let alone while standing by her side on stage. Plus, when you're nervous, it's hard to hear, it's hard to breathe, and it's hard to be present. These are all important things when you are singing!"

Read More: Throwback Thursday: A Preteen Tracee Ellis Ross Tagged Along With Mom Diana to Glitzy Events

As Ellis Ross continued to describe the experience, she also paid tribute to her mother's devotion to her children. "All my life I have witnessed her as Diana Ross the icon and Diana Ross the mother, and I have experienced her seamlessly bridge this incredible dichotomy with grace and ease," she wrote. "She is a nurturing and fierce mom, intimate and ancient, in a setting that isn't meant to support mothering: on stage with the whole world watching. There is a way in which she creates privacy and makes space for the sacred in the most public of settings. It is profound, and defines an infinite depth and wisdom that my mom holds. She has always carved out space for her children. I have always known I was the priority.

"My favorite part was me burying my head into her shoulder," she said in closing. "It has been ages since I've hidden so deeply in my mother's embrace and it was awesome."

Watch the performance below.

Check out the gallery below for singers who have guest starred on TV!

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