Just thinking...
Here's a rough path drawing that could do the job:
\version "2.19.19"
\markup {
\combine
\with-color #magenta
\path #0.3 #'(
(moveto 1.17 -0.50)
(curveto 1.24 -0.53 1.33 -0.43 1.24 -0.36)
(curveto 0.76 -0.07 0.82 0.57 1.49 0.62)
(curveto 2.50 0.60 2.54 -0.65 1.77 -0.84)
(curveto 0.89 -1.02 0.50 -0.54 0.35 -0.20)
(curveto 0.26 0.00 0.07 0.63 1.18 1.77)
(curveto 2.04 2.70 2.19 3.28 1.81 4.20)
(curveto 1.63 4.62 1.52 4.71 1.49 4.76)
(curveto 1.47 4.79 1.43 4.79 1.40 4.76)
(curveto 1.09 4.51 0.84 4.15 0.82 3.70)
(curveto 0.80 3.00 0.88 2.70 1.03 2.15)
(curveto 1.35 1.00 1.48 0.51 1.69 -0.90)
(curveto 1.93 -2.80 0.68 -2.44 0.57 -2.09)
(curveto 1.30 -2.34 1.25 -1.07 0.49 -1.39)
(curveto 0.32 -1.48 0.23 -1.61 0.28 -1.90)
(curveto 0.39 -2.72 2.12 -3.04 1.85 -0.95)
(curveto 1.62 0.70 1.52 0.90 1.21 2.10)
(curveto 0.75 3.46 1.14 3.90 1.64 4.20)
(curveto 1.86 3.49 1.70 3.05 1.10 2.31)
(curveto 0.08 1.24 0.00 0.80 0.00 0.45)
(curveto 0.00 -0.51 0.73 -1.20 1.72 -1.00)
(curveto 2.98 -0.72 2.80 1.15 1.45 1.04)
(curveto 0.50 0.95 0.52 -0.25 1.17 -0.50)
)
\translate #'(0.015 . 0)
\musicglyph #"clefs.G"
}