It was similar in NYC with WNCN, and in San Francisco with the old and current iterations of KDFC. The concept was/is to treat the music like it was an AOR station, with rotations based on how familiar and popular any piece (or movement, for full symphonies or concertos) was. So for example, they might play the first movement of Beethoven's 5th a few times a day because everyone knows it, but the more obscure second movement might only get aired once or twice a week. Also, shorter pieces provided the ability to break more often, run more spots, and generally have more programming flexibility.