Editing Short octave (section)

==Broken octave==

[[File:FEINTES BRISEES.jpg|thumb|This harpsichord built by Clavecins Rouaud of Paris employs the broken octave scheme.]]
A variant of the short octave added more notes by using [[split key]]s: the front part and the back part of the (visible) key controlled separate levers and hence separate notes. Assume the following keys:

:E F F{{Music|#}} G G{{Music|#}} A

with both F{{Music|#}} and G{{Music|#}} split front to back. Here, E played C, the front half of the F{{Music|#}} key played D, and the (less accessible) rear half played F{{Music|#}}. The front half of the G{{Music|#}} key played E, and the rear half played G{{Music|#}}. As with the short octave, the key labeled E played the lowest note C. Thus, playing the nominal sequence

:E F{{Music|#}}<sub>(front)</sub> G{{Music|#}}<sub>(front)</sub> F F{{Music|#}}<sub>(back)</sub> G G{{Music|#}}<sub>(back)</sub> A

the player would hear:

:C D E F F{{Music|#}} G G{{Music|#}} A

The actual note assignments can be seen in the following diagram:

:[[File:BrokenOctaveOnC.svg|200px|none]]

It can be seen that only two notes of the chromatic scale, C{{Music|#}} and D{{Music|#}}, are missing. An analogous arrangement existed for keyboards with G instead of C at the bottom.

According to [[Trevor Pinnock]],{{sfnp|Pinnock|1975|pp=126–131}} the short octave is characteristic of instruments of the 16th century. He adds, "in the second half of the 17th century, when more accidentals were required in the bass, 'broken octave' was often used."

[[File:VienneseBassOctave.jpg|thumb|300px|The Viennese bass octave, as seen in a small single-manual harpsichord kept in the music collection of the Czech National Museum in Prague.  The museum describes it as "anonymous, South Bohemia or Austria, ca. 1700"]]

===Viennese bass octave===

The short/broken octave principle not only survived, but was even developed further in one particular location, Vienna. The "Viennese bass octave" (German: "{{Lang|de|Wiener Bass-oktave}}") lasted well into the second half of the 18th century. {{harvtxt|Gerlach|2007}} describes this keyboard arrangement as follows:
<blockquote>
The notes leading down to F<sub>1</sub> were accommodated on the keys of a "short-scaled octave" from ''c'' to ''C'' (only ''F''{{Music|#}}<sub>1</sub> and ''G''{{Music|#}}<sub>1</sub>, as well as ''C''{{Music|#}} and ''E''{{Music|b}} continued to be omitted.<ref name=G-VII />
</blockquote>
The assignment of notes to keys, which strikingly included a triple-split key, was as shown in the following diagram, adapted from {{harv|Maunder|1998}}:

:[[File:VienneseBassOctave.PNG|350px|none]]

[[Richard Maunder]] (who uses the term "multiple-broken short octave") observes that the Viennese bass octave, like its predecessors, imposed distortions on the string scaling of the harpsichord: it "leads to extreme foreshortening of the scale in the bass." Hence, it required unusually thick strings for the bottom notes, on the order of {{convert|0.6|to|0.7|mm|abbr=on}}.{{sfnp|Maunder|1998|p=44}}

The Viennese bass octave gradually went out of style. However, Maunder notes instruments with Viennese bass octave built even in 1795, and observe that advertisements for such instruments appear even up to the end of the century.{{sfnp|Maunder|1998|p=47}}