We will be visiting Salzburg in September, following the Steves Prague/Budapest tour. I am overwhelmed with the venues for classical music in Salzburg. Sept 18-19 will probably be our evenings for concerts. We will also be there on Sunday morning. Suggestions for hearing a mass in a cathedral? Thanks.
The best churches for music are Franziskanerkirche and the Cathedral (Dom). Both have their resident orchestra and choir; the high masses with orchestra are on Sunday at 9am at Franziskaner and at 10am at the Dom. Arrive in advance as benches get occupied fairly quickly. Franziskaner have a slightly better acoustics and two concert organs (one baroque-style and one romantic); the Cathedral has five organs (one renaissance, one Italian, two German late baroque and a big romantic) - the concert improvisation with five organ players usually held in August is very interesting.
Programs for music in both churches are easy to find on the web.