Shamelessly stolen from around the web and gently modified to use here, I give you:

Murphy’s Laws for Susie Duprey:

• The music stand you get will wobble.
• Singers late for rehearsal are always those who sit in the first row.
• The longer the rests, the less likely a section will enter after them.
• At least one music folder will be left behind after each rehearsal.
  It will usually belong to the same singer.
  If it is not the same singer, there will be no name in the folder.
• Even if everything is explained perfectly, there will still be a question.
  You will have just answered the question one minute before it was asked.
• At least one name will be left off the concert program.
  It will be the wife of the largest sponsor’s president.
• If there are two ways to spell a name, the wrong one will be selected for the program.
• If the audience can clap at the wrong time, they will.
• At concert festivals, three other choirs will sing your toughest piece.
  All three perform before you do, and sing it better.
• Give a strongly-worded lecture about punctuality and you will be late to the next rehearsal.
• At least one mobile phone will ring during a rehearsal.
  You will have explicitly given a speech about turning them off just minutes before.
• At least one member of the chorus will forget to change the key with everyone else. They will be singing the loudest
• If there is a long, dramatic fermata in the piece, at least one singer will keep singing.
  He will be a bass.
  He will sing fortissimo.
  He will sing out of tune.
• And my favorite: The least believable sentence in conducting: “One more time”

You know we love you…