As with a number of the pieces in Book 7, this madrigal is built mostly on closely imitative entries of the duetted voices, staggered to different degrees within a relatively narrow range. If there is a weakness here, its perhaps the overabundance of suspensions, which are the main contrapuntal/compositional device used. Almost every time the second voice in the imitative sequence enters, the first freezes on a high note, creating a chain of suspensions over the other's line. Why the many suspensions become tiring here and are ravishing elsewhere in the book is difficult to say.
The overall tightness of conception more than saves the work. It's evident in the melodic style also; his relatively short phrases are often divided into two clear sections. The first half is a sixteenth-note melismatic flourish, a quick sharp exclamation like a sudden jab of pain, followed with a long high note and perhaps a little ornament at the tail end. Occasionally this is reversed, or substituted for an upwardly drifting, languid chain of notes, but an impression of exceptional single-mindedness remains. It would be fitting to talk about this piece as an abstracted take on the recitative; freed from any dramatic function, the recitative-like music moves unhurriedly through intelligent speculative possibilities. Monteverdi's genius is searching for new effects, and finding them.