From an on-line review of Mad Songs:

A delightful collection of songs from 17th century British composers, reflecting that period's fascination with insanity. The mad song became a favoured genre amongst Restoration composers, who delighted in setting their imaginations free to write inventive and impassioned music for the eloquently rambling flights of fancy of men smitten by madness, most usually caused by the bitter darts of love. This disc brings us some of the best of these songs and ranges from Purcell to Blow. Most of these works would have reached audiences as part of plays, although Blow's Lysander, for example, stands free of theatrical ties. The disc opens with Purcell's Mad Bess, the forerunner and model for mad songs of this period, yet, one could argue, a culmination in the genre – a song that was never bettered.

What a hoot, eh? For more:

Mad Songs