Editing Short octave (section)

==Short octave==
===First type===
One variant of the short octave system was employed in the instrument shown above. Here, the lowest note on the [[keyboard (music)|keyboard]] was nominally E, but the pitch to which it was tuned was actually C. Nominal F{{Music|#}} was tuned to D, and nominal G{{Music|#}} was tuned to E. Thus, starting at the lowest note on the keyboard and playing these keys:

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

the player would hear the [[musical scale]] of [[C major]] in the bass:

:C D E F G A B C

The actual note assignments can be seen in the following diagram, which shows the lowest eight keys of an early keyboard:

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

The rationale behind this system was that the low notes F{{Music|#}} and G{{Music|#}} are seldom needed in [[early music]]. Deep bass notes typically form the [[inversion (music)|root]] of the chord, and F{{Music|#}} and G{{Music|#}} chords were seldom used at this time. In contrast, low C and D, both roots of very common chords, are sorely missed if a harpsichord with lowest key E is tuned to match the keyboard layout. When scholars specify the pitch range of instruments with this kind of short octave, they write "C/E", meaning that the lowest note is a C, played on a key that normally would sound E.

===Second type===
A second type of short octave used the keys
:B C{{Music|#}} D{{Music|#}} C D E F{{Music|#}} G
to play the [[G major]] scale
:G A B C D E F{{Music|#}} G.
Here, the exotic bass notes C{{Music|#}} and D{{Music|#}} are sacrificed to obtain the more essential G and A. The notation for the pitch range of such an instrument is "G/B". The following diagram illustrates this kind of short octave:

:[[File:ShortOctaveOnG.PNG|200px|none]]

In stringed instruments like the harpsichord, the short octave system created a defect: the strings which were tuned to mismatch their keyboard notes were in general too short to sound the reassigned note with good tone quality. To reach the lower pitch, the strings had to be thickened, or tuned too slack. During the 17th and 18th centuries, harpsichord builders gradually increased the size and bass range of their instruments to the point where every bass note could be properly played with its own key.

Short octaves were very common in the early [[Organ (music)|organ]]. Here, the practice would not have yielded poor tone quality (since the associated pipes would have to be built with the correct length in any event). Far more than on stringed instruments the financial savings would have been quite considerable, as the long pipes entailed quite an expense, even in materials alone. But as harmonic music developed more complexity in the late 17th and 18th centuries and the desire arose for completely chromatic bass octaves, short octaves ultimately came to be abandoned in organs as well.

===History===

The 18th-century author Quirinus van Blankenburg suggested that the C/E short octave originated as an extension of keyboards that went down only to F; the addition of just one key (nominal E) and the reassignment of the F{{Music|#}} and G{{Music|#}} added three new notes to the bass range. Van Blankenburg says that when the short octave was invented, it was called the "new extension" for this reason.<ref>Quoted from {{harvp|Hubbard|1967|p=237}}</ref> According to [[Frank Hubbard]], harpsichords and organs of the 16th and 17th centuries "almost always" had short octaves.{{sfnp|Hubbard|1967|p=5}}

[[Edward Kottick]] notes that the short octave persisted for a long time, suggests that a kind of mutual inertia between composers and instrument builders may have been responsible:
<blockquote>
Our forebears were much more practical than we are. Since nobody wrote music that required those notes, why go to the expense of putting them in? And what composer would bother to write them if few keyboard instruments had them?{{sfnp|Kottick|1987|p=32}}
</blockquote>

A transitional stage toward the final adoption of chromatic keyboards was seen in certain English [[virginals]] of the later 17th century. On these the lowest key could pluck two different strings, depending on the slot in which its jack was placed. One of these strings was tuned to low G (the normal pitch of this key in the G/B short octave) and the other to whatever missing chromatic pitch was desired. The player could then move the jack to the slot that provided the desired note, according to the piece being played.{{sfnp|Hubbard|1967|p=151 fn.}}