Amy Winehouse, 27, canceled part of her European tour on Sunday after she was booed on stage Saturday.

The British singer made fans unhappy when she was an hour late for a concert in Serbia, then acted strangely. She was unable to remember lyrics to her songs, mumbled as she sang, dropped the microphone and occasionally simply walked off stage. Concertgoers booed, and many left.

It was the kick-off show for what was supposed to be a 12-date tour of Europe, but Winehouse has now canceled a Monday show in Istanbul and a Wednesday show in Athens, with her reps saying they were still determining whether she would continue with the remaining dates.

Winehouse apologized to fans in a statement, saying she felt the cancellations were "the right thing to do" because she "cannot perform to the best of her ability."

She has struggled with drug and alcohol abuse for years. She recently spent a week at a London rehab program. Her song "Rehab" became a massive hit in 2007, off of her 2006 album "Back to Black," which won five Grammys. Winehouse has not released an album since.

What do you think of Amy's performance? Would you have left?