(define-public (process-music music function)
"Process all nodes of @var{music} (including @var{music}) in the DFS order.
Apply @var{function} on each of the nodes. If @var{function} applied on a
(define-public (process-music music function)
"Process all nodes of @var{music} (including @var{music}) in the DFS order.
Apply @var{function} on each of the nodes. If @var{function} applied on a