Air on the G String original. Later, a spurious story was put about that the melody was always intended to be played on the G string alone. The violin solo part of Wilhelmj's arrangement is sometimes played on the counter-tenor violoncello. As a result of the popularity of the piece, "on the G string" remained in the name of various arrangements whether or not a string instrument playing on its G string was involved. Most of these versions have in common that the original melody of the first violins is played in the low register of a solo instrument, accompanied by a reduction of the
Richter-tuned harmonica note downwards in pitch. This allows for every note on the XB-40 to be bent downwards a whole-tone or more, whereas on standard diatonics only certain notes (the higher-pitched in the cell) will bend at all. The other Richter-tuned harmonica of this kind is the Suzuki SUB30 Ultrabend. Where the XB-40 uses valves and a total of 40 reeds, the SUB30 takes a different approach. Each hole of the harmonica houses a third reed, totalling thirty reeds altogether and thus, where the harmonica draws its name. The third reed is dubbed a "sympathetic reed", tuned one tone below the pitch