Nico
Muhly,

*While I’m aware that it is very difficult to produce variable dynamics on a pedal bass drum, the passages marked piano possible should be played with as much delicacy as is possible on the instrument. To that end, two bass drums may be used: one more muffled, for the softer passages, and the other left unmuted for the louder marcatissimi strokes.

NICO MUHLY (2002)