- Eva Helenius
(b ?1717; d Stockholm, Sweden, 1772). Swedish maker of clavichords and harpsichords, active in Stockholm. Broman was the first builder to put into practice the novel harpsichord and clavichord construction ideas of the Royal Academy of Science, which were an important starting point for the development of the eventual distinctive Swedish school of clavichord design. In 1756, the Academy applied for instrument-making privileges on Broman’s behalf, stating that he had been the first to implement these ideas. At that time, Broman had recently completed a harpsichord built according to the theories of Academy Fellow and mathematician Jacob Faggot (1699–1777). Broman next made a clavichord following the same principles. The Academy’s goal was to provide the domestic market with superior instruments that stayed in tune throughout seasonal humidity and temperature changes, surpassing those by foreign makers as well as by Swedish makers whom the Academy considered to be ‘mere copyists’ (of mainly North German instruments). Broman utilized Faggot’s Pythagorean scaling designs, which maximized use of iron strings of the same diameter. For harpsichord construction, the very long bass strings’ amplitude of vibration proved too great to be practicable. With the clavichord, however, the string lengths could be nearly doubled quite far down to the bass; brass overspun strings were used to compensate for foreshortening in the extreme bass....