For introverts loving taking pictures, a music concert is one of the good situations to hone their photography skill. One reason is the situation doesn't require you to interact and direct the subject. This will allow to focus solely on capturing the moment, energy and expression of the musicians on stage, as well as mastering the tool you have (camera settings, choices of angle, etc.).
Attending a music concert then becomes a time for me to have fun with photography and experiment in a 'safe' environment. When the music plays, everything is just natural: the vibe of the crowds, the musicians' energy and adrenaline, facial expressions for close-up shots, the photo opportunity is rich.