the desire for concerted effects grew, the compass was gradually stretched to three or four octaves or even more.
In most early organs, to avoid expense, the lowest octave was usually
'short,' that is, not only without all of the semitones (or even without
some of the diatonic keys), but with the keys disposed in some peculiar
order so as to bring them close together. This was specially common in
pedal keyboards.
The original application of the keyboard was probably to the
organ proper. But it was early extended to small portative
organs or 'regals,' which were very popular through the later
Middle Ages; and it was on such domestic instruments that the
modern measurements of the keys became established. From
at least the 14th century it was also applied to the monochord,
producing the rudimentary clavichord, and to some form of harp
or lyre, producing the spinet, virginal and harpsichord. Finally,
as the 17th century closed, it was applied to the dulcimer, producing
the first form of the pianoforte. When all the artistic
consequences of these applications are considered, the keyboard
is seen to be most interestingly related to musical progress (see
sec. 135).
102. The Organ.—Among mediæval instruments the organ
was conspicuous because used in church services. At least as
early as the 13th century it appeared in several forms or sizes.
The largest were those permanently set up in churches as part of
their fixed furniture. Next came the 'positives,' which were of
moderate size and could occasionally be moved as convenience
required. Next were the 'portatives,' which were small enough
to be carried about in processions or applied to purely private
and secular entertainment. Finally, there were still smaller
forms, often called 'regals,' which were made so as to fold together,
often in the shape of a large book (hence often called
'Bible regals'). It is natural to think of the larger forms
as connected with the historic importance of the organ, but
the portatives and regals were really more significant. While
church organs were meant solely to support and intensify the
unison Plain-Song or some stiff counterpoint, and were coarse
and strident in tone and awkward to play, the smaller forms
could be used for all sorts of tonal experiments, were often sweet
in quality and relatively easy to play, being distinctly conducive
