It seems there is more than weight rumours troubling the blonde singer, as while performing at a concert in Michigan on Thursday, she reportedly forgot lyrics, mumbled and seemed to be holding back tears for the 38-minutes she was onstage.

RadarOnline. com reports that she held on to her ear pieces, trying to keep them in place, throughout one of her signature songs, 'These Boots Were Made for Walking', complaining complaining she couldn't hear herself.

Then, forgetting the lyrics to her single 'Come on Over', she apologized to the audience, after which during the up-beat 'Pray Out Loud', she stopped her bad and started the song over.

'My voice is weak tonight,' she told the crowd seemingly supportive of the singer, while during her performance of closing song 'Do You Know', she wanted to 'walk off the stage', and thanking her band for 'having her back', as she walked of the stage, it looked like she was wiping away tears.

Her representative told TMZ: 'Jessica had an off night. She's a perfectionist and wanted to start some songs over. She always wants to give the best performance for her fans.'

With the cost of tickets as much as $57 to $200, you can be certain the audience didn't really appreciate the fact that Simpson wasn't game for the show.