Measure the width and depth of your drum. Add half of the depth to the size of the width. Say, for the sake of example, the width of the drum was 16 inches and the depth was 4 1/2 inches. Add 16 inches plus 2 1/4 inches to equal 18 1/4 inches.
Trace an 18 1/4-inch circle onto the dull side of a 1-mm-think canvas sheet with a piece of standard chalk. Cut out the circle with a pair of scissors.
Place the circle atop a second sheet of dull-side-up canvas. Trace the circle. Remove the circle. Cut out a second circle from the second sheet of canvas.
Measure the diameter of your circle. Select a flexible nylon zipper that matches the diameter. Turn the first circle over so the bright side is facing up. Sew one half of the zipper over the outside rim of the circle 1/2-inch removed from the edge using a cross stitch pattern.
Turn the first circle over so the dull side is facing up. Place the second circle over the first one so the dull sides face each other. Sew one half of the zipper over the outside rim of the second circle 1/2-inch removed from the edge using a cross stitch pattern.
Sew the remainder of the canvas edges together with a cross stitch pattern.
Lay a 1-by-6-inch canvas strip 1 inch under the zipper on the top side of the bag. Adjust the strip so it is parallel to the zipper. Sew 1/2 inch of the right end and a 1/2 inch of the left end of the strip into the top side of the bag using a cross stitch pattern. The strap acts as a handle to the bag.
Flip the bag over. Lay a second 1-by-6-inch canvas strip 1 inch under the zipper. Adjust the strip so it is parallel to the zipper. Sew 1/2 inch of the right end and a 1/2 inch of the left end of the strip into the top side of the bag using a cross stitch pattern. Both handles are now in place.