VIDEO : 'Mamma Mia!' Sing-Along Stuns Fans

LONDON (Reuters) - Amid olive trees and plenty of ABBA tunes, the musical world of ?Mamma Mia? took over a London theater on Monday for the film sequel?s world premiere with Oscar winner Meryl Streep and pop diva Cher among the attendees. Ten years after the movie version of the hit theater musical, ?Mamma Mia! Here We Go Again? sees old faces return and new ones join the ABBA sing-along set on a picturesque Greek island where stars belt out tracks by the hugely popular Swedish band.