By Daniel Schantz It was a covert invasion of the world. Pianos began showing up everywhere, beginning in the 1920s, quietly infiltrating homes and schools, churches and clubs, theaters and malls, bars and restaurants. Even wilderness camps, remote mission fields, and sod huts on the prairie soon had pianos. Little wonder the 20th century was called “the golden age of the piano,” and the piano was dubbed “the most popular musical instrument in the world.” Learning to play the piano was a rite of passage for many American children back then, a part of fine breeding, before our children were seduced by soccer and