Pasha Gorki was an agent of the Soviet Union who alongside his military brother Anton sought to use the synthesizer created by criminal Anton Allegro to defeat his country and the U.S. To this end, as the Mad Maestro he mentally controlled Superman, Wonder Woman and Flash and sent them against the new Justice League of America including Steel. Towards the end of this conflict, it was Allegro himself who defeated Pasha at the cost of his life, assisting his old foes of the League of Earth-One.
Roger Romaine was a disenfranchised colonel who sought to use devices of his own creation such as a sonic stunner for revenge. As the Gadgeteer, he found a formidable adversary in Earth-Two's Steel, who eventually defeated him. Whether Roger survived this confrontation is unknown, although later another sonic-based villain known as the Mad Maestro aka Hector Bauer would battle the Justice Society and like Allegro would find his short lived career ending in defeat.