Sixteenth index within the bar, 0..15.
OptionalprobabilityChance the slot is taken before the dial leans on it.
OptionalslotDraw address for the slot; slots that may sound must name one.
OptionalbarRestrict the slot to bars of one parity, for a two-bar figure.
OptionalsectionsSections the slot is added in; absent means every section.
One onset of a kick figure.
A slot with no probability is part of the figure itself and always sounds. One with a probability is where the rhythmic dial reaches the kick: the draw is fixed by position and leaned on by the dial, so raising the dial fills slots in without emptying any that were already there.