We will be in Salzburg one day in September, and want to attend a late afternoon or evening concert of some type. Which one would you recommend?
We have gone to the small (1-2 performers) recitals at the Residence several times. Very nice, short performances. No costumes or kitsch. Tickets sold at the door, as I remember.
You might want to see what's on at the Mozarteum (music conservatory).
For concerts aimed at the Salzburg community (and not just tourists), it's always worth checking the calendar of the Salzburg Cultural Association. I would see the Shostakovich concert in a heartbeat if I were there when it was scheduled (though it would mean no Mozart in "the city of Mozart" [though he hated Salzburg]).
I should add that the Mozarteum shows mentioned by Janet are also aimed at the Salzburg community in general, not just tourists.