Mel B performed energetically at the Spice Girls' 30th anniversary concert in London.
Fans filled the O2 Arena.
Melanie C said the show was heart‑warming.
The night was clouded by a reported feud inside the group recently reported.
The dispute centres on management and royalties.
The event marks three decades since the group first burst onto the scene.
Later that day Mel B appeared as a temporary judge on America’s Got Talent.
A teenage singer took the stage and earned the show's golden buzzer right after the final note to cheers.
The buzzer sent the act straight to the live shows.
Cowell pressed it in a flash.
Mel B said the singer showed great confidence.