Many of Paris’s beautiful churches hold classical music concerts throughout the year. For around 20 euros, you can hear a beautiful concert in Notre Dame, Ste. Chapelle, St. Severin, to name just a few. The concerts vary, from organ to string quartet to piano and more. You can get information from the churches themselves or on posters throughout the city, or go to the AMP Concerts Web site to see what the upcoming schedules are.