In 1871 Mr. Zimmermann was issued a patent for this invention from the United States Patent & Trademark Office (USPTO). There are 2 documents included with this patent. The drawing specification sheet of the patent has been reproduced from original USPTO documents and printed onto parchment paper. This print is sized and ready to install into an 8" x 10" frame. The additional sheets included are printed on 5.50" x 8.50" parchment paper. These accompanying documents describe the scope of this invention in formal terms. The following is an actual excerpt from the patent…

       " Be it known that I, CARL FRIEDRICH ZIMMERMANN, of the city and county of Philadelphia and State of Pennsylvania, have invented a new System of Self-Instruction for Accordions; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawing and to the letters of reference marked thereon. My invention consists of a system of lines and figures which can be played in the same time as notes; and also of a method whereby the said system of lines and figures can be applied to the various German accordions"…