Almost nothing is known about life of Dario Castello. In 1621 and 1629, volumes 1 and 2, respectively, of his sonatas were publised in Rome, and there seems to be no other material which tells about Castello. The category of music style "sonata" is considered to come originally from "canzon". In the end of 16th century, pieces named "sonata" was written by, for example, Gabrieli. There seems to be no publication of sonata collection in a scale like Castello's works, however, before the volume 1 in 1621.
The sonatas in the volume 1 contain very novel and original feeling with much freer style in comparison with the older style of canzon. In the volume 2, the sonatas are further more original, and very progressive even if we consider various music genre in the modern age. The first two solo sonatas with basso continuo in the volume 2 are especially prominent. The piece introduced here, "Sonata Prima a Sopran Solo", may be composed principally for violin, and it is also fine to be performed by recorder in c, or by recorder in g which was used as a solo instrument in the early 17C, if the whole piece is transposed. It is also possible in principle to be performed by cornetto, but I do not know such a recording.
Then, the melody in the beginning develops. The listener's tension is a little bit relaxed in a slower tempo. The melody in minor key changes to major for a moment, and takes a cadence in major.
Next part, usually performed in a very slow tempo, corresponds to slow movement of a sonata in the later ages. It contrasts with the virtuoso part just before, but, in a sense, is very important since character of the player is straightly shown.
The tempo becomes slow in the final part of the sonata. Castello finished this piece in an incomplete cadence accompanied by cromatic grace notes, which he sometimes adopted in other sonatas in the volume 2 as well (I call this "cadence da Castello" with no authorization).