I think that Sainte Chapelle has concerts and I also think that Saint Sulpice does also. Does one need to get reservations in advance.

I've been to many church concerts and have never had to book tickets. For St Chapelle, I might, at least for convenience, pick up tickets while I was visiting to see the stained glass (which is what I did).

I did the same as Michel - I picked up tickets for a concert at Sainte-Chapelle as I was about to see the inside. The clerk actually helped me return my S-C ticket, as the concert I was seeing was during daylight hours, so I could see S-C as part of my concert admission (which was 25 euros).

I've actually seen posters for quite a few concerts at different venues, but all look like you can just show up 30 minutes prior and buy tickets.

There are regular concerts in probably at least a dozen or more churches in central Paris, it's very common. These concerts are not usually sponsored by the church, it's just a venue for the players. Ste Chapelle is different as it's not really a church,just a monument (at least now). Anyway, you don't need reservations in advance for most of these, they are rarely close to full as churches are large. Some very special performance or group may be an exception (eg, there were few tickets at the door to a performance I went to once by a wellknown Russian choir in St-Louis-en-Ile). I've never seen anything that would require buying in advance at Ste Sulpice. Ste Chapelle has many concerts all year of the same repertoire they've been performning for literally years now for tourists, so don't see why you'd need to buy in advance.

Vivaldi's Four Seasons seems to be a favorite at S.C.

If you pick up thee weekly Pariscope or Officiel des Spectacles at newspapaer shop, you'll get a long listing.

Thanks to all for the info.