One of them was scheduled to leave for Turkey as an exchange student. It was only when two of its four members were about to retire from the field of amateur music, however, that the APO, then known as the Apolinario Mabini Hiking Society, finally had a city-wide audience. Just out of college, the group was the talk of the Ateneo University and adjoining campuses for their music and humor. The APO HIKING SOCIETY first gained recognition in 1973 when they gave a farewell concert at the plush Meralco Auditorium in Metro Manila.