New in version 2.0.
Iterate chords backward in expr:
abjad> staff = Staff("<e' g' c''>8 a'8 r8 <d' f' b'>8 r2")
abjad> f(staff)
\new Staff {
<e' g' c''>8
a'8
r8
<d' f' b'>8
r2
}
abjad> for chord in chordtools.iterate_chords_backward_in_expr(staff):
... chord
Chord("<d' f' b'>8")
Chord("<e' g' c''>8")
Ignore threads.
Return generator.