Florence + the Machine crossed the pond and came stateside to make a special appearance on tonight's elimination episode of 'X Factor.' The ethereal Flo and her gorgeous voice are no stranger to the show, as she performed on the U.K. version last month. Tonight's (Dec. 15) live performance of 'Spectrum' was the worldwide debut of the song and Florence did not disappoint.

She began her performance with her back to the crowd. The lights dimmed and the singer was surrounded by ballerinas and mirrors. In a silvery, column-like dress, Flo was a couture vision and that beguiling voice was just about the best thing we've heard on the show all season. For her part, Flo was totally lost in the moment, looking to the sky as she sang while her vibrato bounced off the walls of the Nokia Theater in Los Angeles. It was impossible to take your eyes off her. It was even more difficult not to "feel" what emanating from her in this vibrant live display.

There have been many times this season when PopCrush has commented that some of the 'X Factor' hopefuls may have been technically proficient but didn't quite "connect" with the audience or move viewers with the element of passion in their performances. If the current and eliminated crop of contestants want a textbook, flawless and note-perfect example of how to connect with viewers, then they need to DVR this performance and watch it on repeat like 100 times. Flo was on point.

Watch Florence + the Machine Perform 'Spectrum' on 'X Factor'