this may come across as a odd question but last time I was in paris, i was in somewhat of a public place which has an enclosed structure. Below this, there were some girls practicing and it was so cool because you could hear their voices echo loudly. Right outside this immediate area was regular Paris with its bustling cafes, restaurants and city traffic. I want to go back to this place but have a faint memory of where it exactly is. Ring a bell for anybody?