Arco enarmonico (It.: ‘enharmonic bow’)
- Hugh Davies
Special bow for string instruments developed by Luigi Russolo in Milan in 1925. It consisted of a rod wound spirally with wire to give it a slightly ridged surface. The string was bowed in the normal manner, but the result was two distinct notes from the sections of the string on either side of the bow; when only a single note was required, one section of the string could be damped by a strip of cloth affixed along the length of the bow. Strings did not need to be fingered since different notes could be obtained by changing the position of the bow, but normal fingering could, presumably, be used. For multiple stopping Russolo suggested tuning the top three strings to a major triad with the root doubled an octave lower on the fourth string. Depending on the pressure of the bow, the strings produced sounds ranging from a roughened legato to very rapid note repetitions; the timbres resembled those of two of Russolo’s Intonarumori, the ...