They didn't do the wrong or unethical thing though, they played music according to request at a wedding they were hired to play at. Again, it's not the musicians' job to put together the wedding. Sometimes people intentionally request funny music. Why assume the musicians even knew what the bride would look like? You are being judgemental of them now because you know most of the story from beginning to end, but for all the quintet knew at the time it would just sound unusual and the MOB insisted that was okay. You can't just retroactively assume they know how things would pan out and "intentionally" humiliated someone. The party who should be accountable is most definitely the planners.