\version "2.7.39" 
\header {

  texidoc = "The @code{\applyOutput} expression is the most flexible way to
tune properties for individual grobs.

Here, the layout of a note head is changed depending on its vertical
position.
"

}
\layout { ragged-right = ##t }

#(define  (mc-squared gr org cur)
  (let*
   (
     (ifs (ly:grob-interfaces gr))
     (sp (ly:grob-property gr 'staff-position))
   )
   (if (and (memq 'note-head-interface ifs)
	(memq sp '(-2 -3 -5)))
    (begin
     (ly:grob-set-property! gr 'stencil ly:text-interface::print)
     (ly:grob-set-property! gr 'font-family 'roman)
     (ly:grob-set-property!
      gr 'text
      (make-raise-markup -0.5
       (case sp
	((-5) (make-simple-markup "m"))
	((-3) (make-simple-markup "c "))
	((-2) (make-smaller-markup (make-bold-markup "2")))
	(else (make-simple-markup "bla"))
      ))))
  )))

\context Voice \relative  c' {
  \stemUp
  \set autoBeaming =  ##f
  { <d f g b>8
    \context Voice \applyOutput #mc-squared

    <d f g b>
  }
  
}