Stretch the measuring tape to the length of the 2-by-4. Make a mark every eight inches with a pencil. Use the miter saw to cut four 8-inch pieces off of the 2-by-4 to form the legs of the music stand.
Measure four feet on the 4-by-4 and mark it with the pencil. Use the miter saw to cut a 4-foot piece off the board. Cut a 45-degree angle on one end of the 4-by-4.
Place an 8-inch 2-by-4 on one side of the straight end of the 4-by-4. The 2-by-4 will be perpendicular to the other board, lying horizontal when the 4-by-4 is standing on end.
Drive four screws into the 2-by-4, securing it to the 4-by-4. The short edge of the 2-by-4 will be flush with one corner of the 4-by-4, while the long edge will be flush with the bottom edge and the rest of the 2-by-4 hanging off. Repeat this step for the other three 8-inch pieces of 2-by-4 and the other three sides of the 4-by-4. When finished, one short edge from each 2-by-4 will touch the back side of an adjacent 2-by-4. The screws should be fastened two inches apart in a square shape.
Measure a 20-inch by 14-inch rectangle on the plywood and mark it with the pencil. Use the circular saw to cut the rectangle from the plywood. Stand up the 4-by-4, using the 2-by-4 legs to keep it upright. Drill a hole in the shelving in the lower center of the board, and place the shelving board on the angled end of the stand.
Push a screw through the hole in the board and line it up with the center of the angled end of the 4-by-4. Secure the board to the stand by driving this screw until it's tight. Drive four more screws into the board, two inches apart from each other around the center screw.
Use the miter saw to cut a 12-inch peice of 1-by-2 from the 36-inch peice. Use the screwdriver and wood screws to secure the 1-by-2 to the plywood rectangle. Drive a screw an inch from each edge, and drive one more screw in the center, roughly five inches from the screws by the edge.