One of the delights of walking around Paris is finding unexpected charms. Whether it’s a pocket park or an first-time view, it’s always a pleasant surprise.Today we enjoyed finding a familiar string orchestra in the busy Châtelet métro station, one of the prime spots for busker groups — soloists tend to stick to the corridors and landings, where the hard walls carry their sounds further than you’d think.

We first saw this group several years ago, performing under one of the arcades of the Place de Vosges. Since then we’ve bought two of their CDs, which they issue under the name “Le Marais Performers.” They are said to be conservatory students, but there’s no program so it’s hard to tell, and the players change frequently.