One of the most extravagant automatic musical instruments ever built is the Welte Philharmonic Organ. Only six of these organs were made altogether. The museum's exhibit originated in 1916 and is the largest of all. It was then promoted as a "truly ideal home-music instrument for the personage of means". Its price was at approx. $ 22.000 which equaled the value of about 45 Model-T Ford automobiles. It was acquired at that time by Eugene Meyer, Jr., founder of the Washington Post, for his summer residence.

At its arrival in Speyer in the year 1993, this unique instrument with 2600 pipes, that may be played manually as well as automatically via paper-roll control, was in a deplorable condition. Many important parts were missing, the wind-trunks were not airtight, many metal parts showed corrosion and the cabling had become unusable to a great extent.

Upon conclusion of the restoration which was performed by Gotthard Arnold and his team of the "Fachstätte Historischer Musikautomaten" (specialists for the restoration of historic mechanical musical instruments), the Welte Philharmonic was placed on a 12 x 16 m platform with illumination for exhibit in the Liller Halle.