\version "2.14.2"
\pointAndClickOff

<<
	\new Staff
	{
		\clef bass
		R1
		f,,1\p\<
		b,,\!\ff
	}
	\new Staff
	{
		f''1\f\startTrillSpan ~
		f''\<
		b'\!\fff\stopTrillSpan
	}
>>