@code{0}: around center of width, @code{1}: right side.")
(allow-loose-spacing ,boolean? "If set, column can be detached
from main spacing.")
+ (allow-span-bar ,boolean? "If false, no inter-staff barline will
+be created below this barline.")
(alteration ,number? "Alteration numbers for accidental.")
(alteration-alist ,list? "List of @code{(@var{pitch}
. @var{accidental})} pairs for key signature.")