They were there to support the artist who will represent the UK in this year's Eurovision Song Contest.
But Heidi Range couldn't resist flashing her engagement ring as the Sugababes performed for Graham Norton tonight.
The newly-engaged singer was singing live on One's Your Country Needs You!, the BBC's competition to find this year's British representative.
Betrothed: Heidi Range can't stop smiling as she shows off her engagement ring
And as the hopefuls waited in the wings to hear which one would be headed to Norway at the end of May, the girls performed their latest hit and chatted to their host.
Heidi, 26, took the opportunity to show off her diamond, given to her by her TV presenter fiance Dave Berry, who proposed to her on New Year's Eve while they holidayed in India.
As host Graham Norton gushed over the bling, Heidi blushed as her bandmates Amelle Berrabah and Jade Ewen clapped delightedly.
Delighted: Amelle Berrabah (L) and Jade Ewen applaud Heidi's engagement
And night was no doubt pretty special for Jade too, bringing the memories flooding back for the girl group's newest member.
Last year, she was chosen to represent the United Kingdom in the contest. She later finished in 5th place in Moscow with It's My Time.
It was the UK's best placing for seven years after a run of disastrous results.
From Euro to stardom: Last year's UK entry Jade shows off her enviable long legs as she performs with the Sugababes
But what a difference a year has made for the 21-year-old singer, who is now part of one of the UK's most successful all-female group of the 21st century.
And last night, she joined the judging panel alongside music producer Pete Waterman and Strictly Come Dancing judge Bruno Tonioli to rate each of the six acts before they faced a public vote.
And it was a teenager from Essex who not only impressed the celebrity panel with his version of Jason Donovan's hit song Too Many Broken Hearts but also won the hearts of the public.
Essex boy: Joe Dubovie wows the judges, landing him the coveted position of the UK's Eurovision representative
Happy outcome: Joe poses with host Graham Norton (L), Jade and music producer Pete Waterman
Joe Dubovie, 19, reached the final three alongside fellow contestants 20-year-old dancer Alexis Gerred and 19-year-old vocalist Esma Akkilic, winning the public vote after coming in the final two with Gerred.
He also sang a Mike Stock and Pete Waterman song, called That Sounds Good To Me, which he will perform at the contest in Norway on May 29.
He said: 'I'm so so happy, I really can't believe it. Is this real?
'I never believed I'd come this far. The minute I heard the song I thought it was a definite winner.'
Soon to wed: Heidi and fiancé Dave Berry
Read more: http://www.dailymail.co.uk/tvshowbiz/article-1257626/Heidi-Range-flashes-engagement-ring-Sugababes-perform-Britains-Eurovision-hopefuls.html#ixzz0i3VbSlUC