The recitatives were either 'secco,' supported only at intervals by a
few chords on the harpsichord, or 'stromentato,' accompanied throughout
by various instruments in forms having some musical individuality
of their own. In the former style, declamation was utilized in any way
that the story or the character speaking happened to suggest, and ranged
all the way from simple narration or conversation up to passionate declamation.
In the latter style, the recitative verged more or less upon the
'arioso' or informal song, in which rapid or vehement advance in the
plot was less possible.
The arias had come to be cast usually in the da capo form—a first section mainly in the principal key and some homogeneous manner, a second section contrasted with the first in key and manner, and a third section which was either a repetition of the first or an intensified variant of it. This type of solo has great values as a purely musical form, and is cognate with the longer song-forms generally, but it has obvious dramatic drawbacks if used too persistently and stiffly, since, if its text harmonizes with it, it arrests action and exaggerates emphasis on some single incident, situation or sentiment. For musical reasons, also, in this early usage not only were arias introduced by a short instrumental prelude or 'sinfonia,' but at intervals in each of the sections, especially the first, interludes or 'ritornelli' were inserted, echoing or imitating the melodic figures of the vocal part. These instrumental expansions increased the musical interest of the whole, regarded as a highly developed song, but also increased the difficulty of its satisfactory dramatic application. Arias were properly solos, but duets in similar form gradually became recognized as affording room for musical and dramatic climax. In such duets the voice-parts were often handled in somewhat exact contrapuntal fashion.
As media for expression, arias tended to fall into somewhat distinct classes according to their melodic and harmonic treatment and their consequent fitness for certain types of feeling. Thus, the 'aria cantabile' was characterized by a flowing melody, usually in slow tempo, with few skips, and supported by compact harmony, expressive of placid or meditative emotion; the 'aria di portamento' was similar, but with a much bolder melody, marked by sweeping skips and more prominent accents, expressive of heightened, but not agitated, feeling; the 'aria di mezzo carattere' was more declamatory or descriptive in the voice-part and usually provided with an accompaniment of greater importance, particular species being the 'aria parlante' or talking aria, in which the forcible enunciation of the text was the special feature, the 'aria all unisono,' in which the voice was either unsupported altogether or merely doubled by a few instruments, and which depended for its effectiveness upon the vigor and harmonic suggestiveness of the melody alone, and the 'aria d'imitazione' or imitative aria, in which a point was made of the imitation (usually more in the accompaniment than in the voice) of such sounds as those of bird-song, moving water, festal pomp or warfare; and the 'aria di bravura' or 'd'agilità,' in which every device of vocal virtuosity was employed, including elaborate runs or 'divisions,' pro-
