% versions 2.18.2 through 2.19.83 ok 

#(define (*-markup-list? x) 
  (and (list? x) (markup-list? (remove (lambda(y) (equal? * y)) x))))

listnumber = 
#(define-music-function (parser location listarg numberarg) 
  ((*-markup-list? '()) number?) 
  (let ((str (number->string numberarg)))
    #{ 
      c''1-\markup $str
    #}))

{
  s1_"markup-list? excludes numberarg's 333: so does a stellated hybrid:"  
  \break
  s1_"\listnumber #'() 333" \listnumber #'() 333 s1 % explicitly empty ok 
  \break 
  s1_"list has markups" \listnumber #(list "44" "*" "66" ) 333 s1 % markup ok
  \break 
  s1_"list has * too" \listnumber #(list "44" * "66" ) 333 s1 % stellated ok
  \break 
  s1_"list has only * " \listnumber #(list * * * ) 333 s1 % all-star ok
  \break 
  s1_"\listnumber 333" \listnumber 333 s1 % omitted ok
}