The final 20 all had to sing in front of Andrew Lloyd Webber and the panel - Charlotte Church, John Partridge and Sheila Hancock - on tonight's show to convince them to put them through to the next stage of the competition.
The hopefuls were divided into groups of four and had to sing one pop song and one West End track to persuade the judges to save them.
Among the final ten are 18-year-old Bronte Barbe, 17-year-old Stephanie Davis and former Page 3 girl Amy Diamond, although Webber said that he is "not quite sure she could be a Dorothy".
18-year-old Jenny Douglas, former X Factor contestant Sophie Evans and Steph Fearon, who has previously starred in Casualty and My Parents Are Aliens, also made the cut.
The youngest contestant, 16-year-old Dani Rayner, joined the lineup after Partridge described her performance as "sensational", Church branded it "absolutely fabulous", and Webber claimed that there was something "very special" about her.
Meanwhile, student Danielle Hope, Miss Dance 2008 finalist Jessica Robinson and 22-year-old Lauren Samuels completed the final ten.
After making the decision, Webber confessed that it had been "really, really hard" to choose the finalists, adding: "Five girls we all agreed on absolutely immediately, and I'm afraid we argued quite a lot about the others. I hope we've made the right choice and I'm really glad the public have the chance to pick another one, because I'm terrified we haven't."
The public will now be able to vote for a "Wild Card" finalist from the ten women who did not make it through.
Either Tasheka Coe, Tegan Edwards, Emma Warren, Emilie Fleming, Claire Harbourne, Claire Hillier, Katie Honan, Camille Mesnard, Sarah Middleton or Philippa O'Hara will be announced as the "Wild Card" choice on next week's show.
Over The Rainbow continues next Saturday at 7.25pm on BBC One.