define-void-function or define-procedure ?

[David Kastrup]

What would people prefer for creating a Lilypond function that returns
an "unspecified" value (what the Guile read-eval-print loop takes as a
hint to print nothing at all) and is called for its side effect?

define-void-function or define-procedure?  The first is a bit more
C-ish, the second more Pascal-ish.  I am not going to consider
define-subroutine though.

-- 
David Kastrup