We are going to attempt to provide enough information here to identify some of the major Recordo systems. To our current knowledge, there have been at least nine major manufacturers of the system. While they all used the same trackerbar layout and the same Recordo music rolls, the expression device, the rotary vacuum pump, and certain automatic and mechanical features are quite different.

In general terms, the Recordo system is capable of producing four levels of music expression (P, MF, F, and FF), using four special holes in the trackerbar, plus the lowest, or zero, level (PP), for a total of five levels. While not used in all Recordo systems, the music rolls can also have Bass and Treble Hammer Rail Lift perforations, which each move half of the hammers (bass or treble) closer to the strings. This effectively lowers the volume of the music. Two other features include the Auto Sustain Pedal and an optional Ukelele or Mandolin Rail, which can be operated from the music roll. Most Recordo systems also offer manual controls for all of the above features and expression levels. That allows the user to play the music with expression when using regular 88-note music rolls. It should also be stated that all Recordo systems can play regular 88-note rolls. The system will not preform correctly if other types of expression or reproducing rolls are used unless the Recordo system is turned 'Off' (some systems offer a Recordo 'On'-'Off' switch in the spoolbox).

The seven major system makers are (1) Motor Player Corp (Electora Recordo System), (2) Wurlitzer, (3) M. Schulz Co. ('Aria-Divina'), (4) Starr Piano Co., (5) Standard (early and later), (6) Auto-Deluxe, (7) Artistone, (8) Amphion, (9) H.C. Bay. Below are the best pictures or diagrams we've been able to find of the expression device for these systems.

(1) Motor Player Corp (Electora Recordo System)
(2) Wurlitzer
(3) M. Schulz Co. ('Aria-Divina')
(4) Starr Piano Co.
(5) Standard (early)
(5) Standard (later)
(6) Auto-Deluxe
(7) Artistone
(8) Amphion
(9) HC Bay

I wrote an email to a gentleman years ago that expresses my feelings about the Recordo system and its many variations. It's titled: Recordo: Which One?. There's also a webpage named: Simplex Recordo. As I locate other information about Recordo systems, it will be presented here.