Music Director Michael Gerdes took the San Diego State University Chamber Orchestra and a cache of other SDSU musicians down to Bread and Salt in Barrio Logan Sunday afternoon to perform an engaging concert of contemporary music. With its high ceiling and unfinished, bare brick walls, the chaste performance space embraces all styles of music. And new music has found a particular sonic welcome in this building that was originally built to produce commercial baked goods in quantity. Arvo Pärt’s energetic yet strangely mystical “Fratres” opened this concert. When the composer first issued this work in 1977, it had no…