mufflePath=
\markup
\path #0.15 #'((moveto -1.25 0)
                (lineto 1.25 0)
                (moveto 0 -1.25)
                (lineto 0 1.25))

muffleMarkup=
\markup \translate #'(0 . 1)
\combine \mufflePath
\draw-circle #1 #0.15 ##f

oMuffleMarkup=
\markup
\combine
\center-align \huge \bold \normal-text "O"
\center-align \translate #'(0 . 1)
\mufflePath


innerMuffleMarkup=
\markup \combine \muffleMarkup
\translate #'(0 . 1)
\draw-circle #.58 #0.15 ##f

muffle=#(make-dynamic-script muffleMarkup)
innerMuffle=#(make-dynamic-script innerMuffleMarkup)
oMuffle=#(make-dynamic-script oMuffleMarkup)

\new PianoStaff <<
  \new Staff {b1 b2 r b r b r \bar "|."}
  \new Dynamics {
    s1\p s2 r\oMuffle
    s r\muffle s2 r\innerMuffle
  }
  \new Staff {\clef bass e1 e2 r e r e r}
>>