Me too ... once, the mother of the bride came up to me just seconds before the entrance processional and demanded different music to be played for the bridal party ... she said they wanted "the Yellow Rose of Texas" which I knew was completely bogus, so I played what myself and the bride & groom had selected which was Jesu, Joy by Bach. As I started to play the Bach, I got the ugliest, sternest, and meanest eye stares ever known to man . . . and of course, I did not get paid afterwards. Felt like flattening some tires when I left. The bride later found out about what "mother" had done, and was upset at her, and proceeded to make sure I was paid for my time.
In another instance , the wedding coordinator believed that the wedding party MUST practice the entrance and recessional at least 10 times on rehearsal night. And so I had to, in some cases, play the gawdawful Bridal March 10 times in a row ... b o r r r r r i n g ... rehearsals lasted nearly 90 minutes for a 17½ minute service ... why?
These were always held on the same night before choir rehearsals. Eventually I put my foot down and said that I would be there to play for 15 minutes only ... and time spent after that 15 minutes would result in an additional $100 fee. And that was in 1967 dollars which was quite the sum.
I can only imagine what bands must go through in situations like this.