The ornamental design for a musicthemedframe, as shown and described.
FIG. 1 is a front perspective view of a music themed frame showing my new design;
FIG. 2 is a front elevational view thereof, wherein the protruding internal detail on the right inner wall of the music themed frame is a broken line and is not part of the claimed design;
FIG. 3 is a rear elevational view thereof, wherein the rear innermost surface inside the broken line is not part of the claimed design;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof, wherein the broken line on the lower edge is not part of the claimed design.