Music Hater (3.5e Flaw)
From D&D Wiki
You can not stand the noise of performed melodies.
Prerequisite: Character must have ears or similarly functioning organs.
Effect: You take a -4 penalty to saving throws against special attacks that are described as using song or music (such as a harpy's captivating song), and against bardic spells. In addition, you suffer a -4 penalty to concentration and a -2 penalty to general reflex saving throws when your character can hear song or music.
Roleplaying Ideas: Perhaps your character grew up in a natural environment and dislikes fabricated sounds, or perhaps they have bad history with a bard.