The ornamental design for a thumbpiano, as shown and described.
FIG. 1 is a top perspective view of a thumb piano, showing my new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a right-side elevation view thereof;
FIG. 5 is a left-side elevation view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is a cross-sectional view, taken at the line 8-8 in FIG. 2;
FIG. 9 is a cross-sectional view, taken at the line 9-9 in FIG. 2;
FIG. 10 is a cross-sectional view, taken at the line 10-10 in FIG. 2; and,
FIG. 11 is a front elevation view of the thumb piano with a portion of the unclaimed thumb piano keys shown cutaway so that the claimed portions of the design are clear.
The broken lines shown in the drawings depict portions of the article that form no part of the claimed design.