Watermarking music sheets, it is possible?

Most of the commonly used applications of watermark are referred to color or gray levels pictorial images but some new fields starts to be considered. Some research was recently done for music sheet protection considering it as b/w image [3][7][16] or considering it as result of printing from music editors [12], [13], [14]. This paper presents the theoretical difficulties to implement watermarking approaches for music sheets. It is not intended to demonstrate the technical impossibility of such techniques but only try to show how much effort is needed in order to develop good approaches in this field.