Stradner, GerhardProceedings of the Third Vienna Talk on Music Acoustics (2015), pp. 92–95
The main-question with regard to early trumpet mutes concerns their transposing interval: Do they raise the pitch by a half-step or a whole step? Modern reference books offer the unsatisfactory answer that both transpositions are possible. Surviving mutes raise the pitch by a half-step, but theoretical and musical sources from the seventeenth and eighteenth centuries specify a whole step. I began my research by comparing surviving mutes, many of which were tested acoustically by Hannes Vereecke with original trumpets, using the Brass Instrument Analyzing System (BIAS). No mute could be found that raised the instrument’s pitch by a whole step, so the research was abandoned. In an effort to solve this problem I read the relevant treatises again, comparing them with music for muted trumpets and evaluating this information in light of performance-practices of the time. The most important consideration here is the necessity for trumpeters to move from Chorton to Cammerton by exchanging bows of different sizes, and also to adjust the mutes when they are used with different bows in order to play in tune in several different keys. It can be shown that upward transposition of a whole tone is the best solution for all situations. All surviving mutes can be used for transposing up a whole step by removing a half-tone-bow (mute minus halftone-bow = two half-steps = whole step up). The variable difference between Chorton and Cammerton of a half-step to a minor third always accommodates this procedure. Many of the remarks on mutes on Altenburg’s Versuch (1795) are incorrect; perhaps he simply copied his information from earlier books. In any case, it appears that a mute for upward transposition by a whole step did not exist during the heyday of the natural trumpet.