1969
The WERSI company was formed by two brothers, Wilhelm-Erich and Reinhard Franz in Halsenbach, Germany, to produce DIY electronic organ kits. These enabled instruments to be built with no previous electronic knowledge. Hardware and Software upgrades would keep the models from becoming obsolete. Between 1977 and 1977 they produced the "W" analogue series, "DX" and "CD" digital series of organs.

1991
WERSI went bankrupt following the development of the WERSI piano and the brothers sell out. The new staff owned, company continued with the manufacture of the Pegasus, Performer, Penta, Phon-X, Rhondo classic etc. Kits were discontinued..

1998
The company goes bankrupt for the second time. All production, hardware and software rights are taken over by Thomas music. Thomas reprogrammed the sounds of some of the later WERSI Organs. These were marketed under the Thomas label under different names. Rhondo classic became Floridian etc. These used the same hardware but different software. Wilhelm-Erich and Reinhard Franz, now form a new company named WERSI music production, with their logo showing WERSI in large letters and "music production" in smaller letters. They produced a new expander, the OX7 that was marketed in the States.

2002
WERSI music production, drop the "music production" from their Logo and go back to WERSI. The WERSI Brothers release the original GS series as the OAS, (Abacus, Scala, and Louvre etc.) A built in computer runs MS Windows with Steinberg Cubase Software.

2005
The company moves back into the original factory at Halsenbach. Wilhelm-Erich and Reinhard Franz leave and Ulrich Wildhack and Torsten Reichold take over the management of WERSI.