For a chance to listen to an hour and a half of classical music in a gilded and chandelier lit atmosphere, go to a Jeunes Talents (young talent) concert. One September Saturday afternoon a few years ago, after a walking tour ended at the Hôtel de Soubise, we stepped into the museum. Although the museum had closed, we were invited to attend a chamber music concert. We have been going back ever since. The concerts held in the National Archives building (Hôtel de Soubise) in the Marais are great value for the money. Music begins at 6 p.m. in opulent surroundings and is a perfect pause before dinner after a…