Shop, lunch, sing and dance on rue Mouffetard, Sunday afternoons
Shop the end of the market, find lunch on the street (perhaps a savory tarte from Maison des Tartes), then wander back down to the foot of the street for singing and dancing to traditional songs.
Grab a table on the terrace of La Bourgogne at 10am for a petit déjeuner on Sunday morning, slowly nibble and sip, and you will have a ringside seat for the "musette" starting at 11. Unfortunately, it's all tango and foxtrot etc. The traditional Paris style of dancing (each partner takes a firm two-hand grasp of the other's buttocks) is rarely seen anymore. And for a zen moment after all the frolicking, drop into the Saint Médard church for maybe a free(ish) choral or organ recital. Paris is a great place for contradictions and incongruity.
"la Mouffe" is indeed a fun quartier and, even better, 3 of my favourite restaurants --- Dans les Landes, Lilane and l'Agrume-- are in the vicinity. But, foodwise, the area's mix of the good and the dire can make for some very unpleasant surprises. And in the peak summer season, the hordes of tourists can sometimes seem like there is a frequent shuttle service straight from the place du Tertre to the rue Mouffetard (with stop-offs at the rue des Rosiers for falafel). But every year la Mouffe survives the onslaught and, by la rentrée, has recovered her real and quite delightfully Parisien character.