Technological Breakthrough

"I measured the frequency of the notes, put them where they were 'supposed' to be, and the piano still sounded bad." This, he says, is the problem solved in practice each time a piano is tuned - and one he was determined to conquer theoretically. His quest began with a cigar box full of electronic components. To perfect his product, Sanderson studied privately with master technician Bill Garlick, former head of the piano technology department at North Bennet Street School. He developed aural skills while the skeptical Garlick served as a research subject. Ultimately both were convinced the box was ready to compete on the market. In 1976 Sanderson left Harvard to focus on the Accu-Tuner, which has since found its way to Italy, Australia, Indonesia, and to the Copenhagen Symphony.

Inventronics has a dozen patents that apply directly to piano tuning instruments and patents on designing bass strings. Discoveries made during the twenty years of research on inharmonicity have been the basis for most of the piano tuning instruments in use today.

Al Sanderson and Jim Coleman developed the Piano Technicians Guild Tuning Exam. The two men were selected for the project by then president of the PTG, Don Morton. The project was to devise a test that could be standardized for uniformity and fairness to the applicants. Al and Jim created a test and then traveled the US extensively giving the test to volunteers, getting sample data to present to PTG Exam committee. The exam was accepted by the PTG and although there have been revisions over the years, it is now the tuning exam for Registered Piano Technician membership to the PTG.

The Sanderson Accu-Tuner provided the standard for the PTG tuning test. Before the SAT there wasn't any means for automatically comparing the candidates tuning with the "Master Tuning" of the examiners. This advance allowed the tuning examiners to reduce the subjectivity of the exam and to reduce the math errors.