As the touchstone of the classical canon, J. S. Bach matters every day of a musician’s life. This program, part of the Australian Chamber Orchestra’s inaugural digital season, juxtaposes peaks of Bach’s sublimity with excerpts from The Reef, an ecological video scored by Richard Tognetti, the orchestra’s artistic director and lead violin. Emmanuel Pahud, preeminent among flautists, joins in the monumental six-part Ricerar from Bach’s Musical Offering (familiar to balletomanes as the finale of George Balanchine’s Episodes). —M.G.