The Spice Girls said they were "excited, humbled and proud" to be at the musical inspired by their music Viva Forever!
The singers also praised the writer Jennifer Saunders as well as the cast of the musical.
The Spice Girls were reunited again tonight for the opening of the musical Viva Forever! in London.
Victoria Beckham arrived 40 minutes after the other four band members with her three sons and husband David.
The singers were joined by the writer of the musical Jennifer Saunders who wrote the show to the songs of the Spice Girls. Tonight she said the show "is not the story of the Spice Girls, it's a story that is inspired by their music".
Geri Halliwell, Emma Bunton, Mel C and Mel B all sat together in the Piccadilly Theatre, reportedly posing for pictures on their mobile phones, giggling and hugging whereas Victoria sat with her husband and their three sons.
Viva Forever! the new musical written by Jennifer Saunders and inspired by the story about the Spice Girls opens in London tonight.
The Spice Girls arrived a short while ago with actress Jennifer Saunders, all are expected to take to the stage at the end of tonight's show.
Former Spice Girl Emma Bunton has admitted that she can't wait for her children to see the West End musical Viva Forever! because they have no idea about their mother's former stardom.
ITV Daybreak's Richard Arnold caught up with the Spice Girls to talk about being reunited and seeing their story on stage:
Spice Girl Victoria Beckham has tweeted about her 'amazing' day back with the band:
Thank u to all our fans for being with us today!! X vb
Thank you girls!Amazing to see u all today!!! Lots of love,Victoria x
The Spice Girls were reunited once more today as they launched a stage musical inspired by their songs, Viva Forever.Read the full story ›
Comedian and writer Jennifer Saunders hopes audiences will enjoy the Spice Girls musical and that they will be entertained.
Saunders says the story has a lot of "emotional content" and a "lot of laughs" and it will relaunch the Spice Girls' music.
She added the musical will have a darker side.
Geri Halliwell says she was holding back the tears when she watched the workshops of the new musical.
Mel C added that the rehearsals gave the girls "goosebumps" and it was a "lovely thing"
The girls said the musical supports Girl Power's longevity. "Who would have thought the message is still standing 16 years later".
At the press launch of 'Viva Forver', Geri Halliwell said the musical supports Girl Power's longevity. "Who would have thought the message is still standing 16 years later".
Spice Girls were in London to launch 'Viva Forever'. Emma Bunton or Baby Spice as she was known said the relationship between a mother and daughter is a big part of the show.