The ornamental design for a portion of a musicalinstrument lamp, as shown and described.
FIG. 1 is a front elevational view, the broken lines showing of the finial,
shade, light bulb, musical instrument body and base being for illustrative
purposes only and forms no part of the claimed design.
FIG. 2 is a right side elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof; and,
FIG. 5 is a top plan view thereof, the bottom being hidden from view in use
.