Anne Ford it was considered controversial for a woman to play the "masculine" viola da gamba, referred to at the time as the "viol di gambo". Ford gave a performance at Spring Gardens in 1761, "English airs". accompanying herself on the musical glasses. She also wrote a published work, "Instructions for Playing on the Musical Glasses". The instrument was comparable to the glass harp of Richard Pockrich consisting of individual glass goblets tuned with water, and preceded the 1761 mechanized armonica (Glass harmonica) invention of Benjamin Franklin and played by Marianne Davies. Ford's accomplishments risked being complicated by an infatuated lover, the
Glass harmonica produce a clear tone. Some attempted improvements on the armonica included adding keyboards, placing pads between the bowls to reduce sympathetic vibrations, and using violin bows. Another supposed improvement claimed in ill-informed post-period observations of non-playing instruments was to have the glasses rotate into a trough of water. However, William Zeitler put this idea to the test by rotating an armonica cup into a basin of water; the water has the same effect as putting water in a wine glass – it changes the pitch. With several dozen glasses, each a different diameter and thus rotating with a different depth,