The tag BAMO refers to exercises in which we pay attention to whether an onset occurs before (“B"), after (“A"), or directly on (“O") the beat. See also 356. other tags: Each/Once/(Spread); No #s; Short-Hand/Patt 1st; Show Beat; Yeasty.
As in the previous example, “B," “A," and “O" mean before, after, or on the beat, respectively.