Dr. Dre Monster Beat headphones are a MUST-HAVE accessory. The ear-buds are acceptable, but the giant metal circumaural ones are preferable. As long as the cord is flame-red, you’re good to go.
The accordion is not dead. It is alive and well in the subway, on the train, at sidewalk cafes, wherever the wandering street musicians decide to go. Concertina is strictly for serenading your own friends.
While I know hiphop is popular in France, the music wafting out of stores and other places is predominantly electronic/dance. You’re more likely to overhear the Chemical Brothers than Beyonce, which is just fine with me.