I cannot comment on any particular knowledge of Musica Sacra happening in the Tucson region, but I do know that the midwinter conclave of the American Guild of Organists held in Tucson back in January was outstanding! They really raised the bar for excellence in every way when it came to organizing the event. Unfortunately, almost all of the venues were in non-Catholic settings. We went to the Catholic cathedral for one of the concerts, but evidence there suggested that the state of liturgical practice there was humdrum. I could be wrong, but doubt it. We did get to venture into one of the less glamorous neighborhoods of Tucson to visit Santa Cruz Parish. I don't know what the state of music is there, but I got the distinct impression that the clergy was very much interested in sacred music. My old boss, Fern Hieb, might be able to give you some advice -- she's active in the AGO chapter there: barryfern at cox dot net.