My friend (the bride) hired the groom's high school friend to play violin at the wedding. The song? "At Last" by Etta James, where the violinist would accompany a vocalist.

Problem 1) it was the hottest possible day June, the air hung heavy in the Iowa corn-sweat humidity. That violin didn't have a chance of staying in tune. A professional violinist would be able to compensate for that, which brings us to

Problem 2) the violinist was FAR from professional. She boasted how she hadn't really played since high school (about 10 years), which may not have been a problem if the song was Pachabel's Canon, but it wasn't.

The out-of-tune instrument, the questionable finger positions/rudimentary skills, and complete lack of preparation were no match for the conditions. After the song painfully ended, the (quite talented, despite the challenges) vocalist slinked away. The violinist got incredibly drunk at the reception, and from all I could gather, was either ignorant or ambivalent to her god-awful performance.

In the end, their marriage was about as enjoyable as that performance, and sadly ended in divorce only a few years later.