【Semi-dokyumento: Tokkun Meiki Dukuri】

If you break a guitar string or Semi-dokyumento: Tokkun Meiki Dukuribust a drumstick in half, that's a pretty quick and easy fix for a live performer -- just grab a replacement. If you lose your voice and singing is your entire job, that's a whole different story.

During a concert in Berlin on Saturday night, U2 cut its set short after just five songs when lead singer Bono's voice became noticeably strained.

Bono was apologetic when he told the audience that he couldn't go on and said he was going to take a short break to find out what happened to his voice, as seen in the video below.

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As you can hear in the video, he has a hard time talking, let alone singing.

The break wasn't enough for Bono to recover and the show unfortunately had to be canceled. In a statement later, the band apologized to fans.

"We don't know what has happened and we're taking medical advice," the statement reads. "As always, we appreciate our audience's understanding and all our fans' support in Berlin and those who travelled from afar. We will update you very soon."

Saturday's show was just the second in U2's European tour, which is set to resume on Tuesday with two shows in Cologne and continue across the continent until November. With any luck, Bono's voice will return before then, but if not there may be more cancellations to come.

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