The murders. On October 26, 1590, Carlo Gesualdo, Prince of Venosa, let it be known to his household that he was going hunting (as he often did) and would be absent from his Naples palazzo for two days. He returned secretly that evening, however, and sometime after midnight burst into his wife's bedroom with three armed servants.
There he found his wife Maria in bed with her lover, Fabrizio Carafa, Duke of Andria. A witness heard Gesualdo order his men to kill the couple, and then the firing of two shots. As he was leaving the room with his hands "covered with blood," Gesualdo was heard to say "I do not believe she is dead!" and turned back to stab his wife's body several more times.
Gesualdo and his men then fled Naples, leaving behind a scene of carnage. Carafa had been shot in the chest and in the head at close range, and stabbed so savagely the points of the weapons gouged the floor beneath his body. Maria had "many wounds" in the head and body, and her throat was cut; her nightdress was "bathed with blood." The lovers had not just been murdered, but butchered. Immediately after the killings Gesualdo and his accomplices probably escaped to the relative safety of his family castle in the town of Gesualdo, about 60 miles east of the city. 
"The Pardon." As an act of penitence Gesualdo ordered the building of a Capuchin monastery near the castle, which was completed over the next few years. Behind the altar of monastery's chapel, Santa Maria delle Grazie, hangs a large painting now known as "Il pardon" (The Pardon). The upper part of the canvas depicts Christ, surrounded by the Virgin Mary, Mary Magdalene, archangels and saints. In the lower part of the canvas Gesualdo himself is shown kneeling next to a fiery pit, from which angels and cherubim are helping a naked man and woman to emerge. All the figures (except Mary Magdalene, who looks at Gesualdo) are gazing imploringly at Christ, who raises his right hand in a gesture of blessing. Is Gesualdo asking for pardon? Or is he pleading for the pardon of the souls of the two lovers, who, surrounded by other sinners, had been trapped in eternal fire?
The second marriage and the first books of madrigals. In 1593 negotiations were concluded for a marriage between Gesualdo and the 32-year-old Eleonora d'Este, a cousin of Duke Alfonso II d'Este of Ferrara. That a powerful family would seek a marriage with Gesualdo just a few years after he killed his first wife demonstrates the degree to which adultery was seen as legitimate grounds for spousal violence. The alliance was advantageous to both families. Duke Alfonso was hoping for greater influence with the Pope through Carlo's uncle Alfonso, who was Dean of the College of Cardinals in Rome. Gesualdo, a self-made widower with only one son, needed more potential heirs.
When Gesualdo arrived at Ferrara, about 70 miles southwest of Venice, for the marriage festivities in February 1594, he carried the manuscripts of his first two books of madrigals with him. These were published in May and June of that year by the printer for the house of d'Este, Vittorio Baldini. These works are highly accomplished examples of the madrigal form, as shown by the piece that opens the First Book, "Baci soave e cari" (Sweet and tender kisses):
The performers are the Czech Soloist Consort; the words are by Giovanni Battista Guarini: "Baci soavi e cari,/ cibi della mia vita/ c'hor m'involate hor mi rendete il core,/ per voi convien ch'impari/ come un'alma rapita/ non sente il duol di mort'e pur si more." (Sweet and tender kisses, sustenance of my life, first you steal, then you give back my heart: you want me to learn how a soul in rapture feels not the agony of death, yet dies.) A characteristic Gesualdo touch is the dissonance on the word "morte" (death) that occurs at around 1:50 in this performance; in his later books, the dissonance and chromaticism would become ever more extreme.
Ferrara and the third and fourth books of madrigals. With one six-month exception when he travelled back to Gesualdo without his new wife, Carlo Gesualdo stayed in Ferrara for the next two years. During this time he was in contact with musical developments at other northern Italian courts, which were renowned for their musical establishments. His third and fourth books of madrigals, published in Ferrara in 1595 and 1596, were probably composed at this time, and are more harmonically daring than his first compositions. Here is "Sospirava il mio cor" from Book 3:
The performers are Delitiae Musicae; the words are "Sospirava il mio core/ per uscir di dolore/ un sospir che dicea: 'L’anima spiro!'/ Quando la donna mia più d’un sospiro/ anch’ella sospirò che parea dire:/ 'Non morir, non morire!'" (My heart was sighing to escape its pain, a sigh that said "I give up my soul!", when my lady also breathed a sigh that seemed to say, "Do not die, do not die!")
Had Gesualdo stopped publishing music after his Fourth Book was issued, he would still be among the most famous composers of the time. He is mentioned in an essay appended to a 1607 collection of Claudio Monteverdi's music as one of the founders of the "second practice" of madrigal composition, in which the words were paramount and the expressive capabilities of music were intended to convey their meaning: a sighing fall on the word "sospira," agitated fast tempos for battle metaphors, dissonances on words such as "pain," "death," "suffering."
However, in his last two books of madrigals Gesualdo took the conventions of chromaticism and dissonance to new extremes.
Return to Gesualdo and the last compositions. In late 1596 or early 1597 Gesualdo returned, permanently, to the town of Gesualdo, and his wife Leonora and their infant son, Alfonsino, joined him in September. There were dark hints in letters and other documents that Gesualdo physically and psychologically abused his wife, and that he had taken mistresses (not unusual, it must be said, for a Renaissance prince). There were also suggestions that Leonora and her half-brother Alessandro were incestuously involved; Alessandro had also had an affair with the sister of d'Este family friend Marco Pio, who feuded with Alessandro, perhaps over the affair, and was later murdered, probably by Alessandro. Ah, the colorful lives of the Italian aristocracy...
In October 1600 the five-year-old Alfonsino became ill and died. There are accounts that after his son's death, Gesualdo was increasingly subject to dark mood swings ("melancholia," which could mean anything from poetic wistfulness to black depression), and that he asked to be beaten by teams of servants:
he was assailed and afflicted by a vast horde of demons which gave him no peace for many days on end unless ten or twelve young men, whom he kept specially for that purpose, were to beat him violently three times a day, during which operation he was wont to smile joyfully. This account should be treated skeptically since it dates from two decades after Gesualdo's death. These rumors have been widely repeated, though, and may be the origin of the idea that Gesualdo was gradually driven mad by remorse and sorrow.
In 1611 Gesualdo published his Responsoria for Holy Week as well as the fifth and sixth books of madrigals, whose dissonance and chromaticism can seem amazingly modern. Here is "Moro, lasso" from Book 6:
The performers are the Gesualdo Consort; the words are "Moro, lasso, al mio duolo/ e chi mi può dar vita,/ ahi, che m'ancide e non vuol darmi aita!/ O dolorosa sorte,/ chi dar vita i può,/ ahi, mi dà morte!" (I die, alas, in my suffering, And she who could give me life, alas, kills me and will not help me. O sorrowful fate, she who could give me life, alas, gives me death.)
In August 1613 Gesualdo's son by the murdered Maria d'Avalos, Emmanuele, died in a riding accident without leaving a male heir; and two weeks later Gesualdo himself passed away. After winding up Gesualdo's estate, his wife Leonora moved to the town of Modena to be with her family, and died in 1637 at the age of 76. The ancient family of Gesualdo died with her.
Do the late madrigals reflect Gesualdo's madness? The author of the prefaces to Gesualdo's fifth and sixth book of madrigals claimed that their appearance in print was "fifteen years from the time when they were composed."  This would place their composition around 1596, at the time the madrigals of the fourth book were published.
For those who see a stark stylistic disjunction between the earlier and later books of madrigals, and who are tempted to read this disjunction as evidence of Gesualdo's increasing mental affliction, these prefaces present a problem. While it's clear that they may be an attempt on Gesualdo's part to establish false precedence, there's also no reason to assume that the music contained in the fifth and sixth books was composed close to the date of publication in 1611: composers of the time often withheld music from publication for private performances, and printed collections were often "best of" compilations that included music composed over many years. Also, those who espouse the idea that Gesualdo's music reflected his growing madness have to explain how a madman would have been capable of writing the complex counterpoint and shifting harmonies of five-part madrigals.
Instead, I think we have to recognize Gesualdo as a highly innovative and self-conscious composer who was deliberately pushing the boundaries of the accepted musical practice of the time. He may also have been "assailed and afflicted by a vast horde of demons," but those demons are more likely to have interfered with his ability to compose, rather than to have inspired it.
Gesualdo's harmonic innovations were not always approved by later listeners. Charles Burney (the father of Fanny Burney) wrote in his General History of Music (1789) that Gesualdo's late style involved "harsh, crude, and licentious modulation" that is "offensive...not only repugnant...but extremely shocking and disgusting to the ear."  However, by the late 19th and early 20th centuries, Gesualdo's harmonic practices seemed to prefigure modern developments in chromaticism, dissonance and atonality. Stravinsky, in his preface to Glenn Watkin's critical biography of Gesualdo, calls his music "powerful" and "revolutionary" (Stravinsky made two pilgrimages to the town of Gesualdo and one to Gesualdo's tomb in Naples). 
The Complete Gesualdo Madrigals. Between 2010 and 2013 the Italian ensemble Delitiae Musicae, under the direction of Marco Longhini, recorded all of Gesualdo's madrigals for the Naxos label. When the project was completed the seven CDs were issued as a boxed set.
As you can hear from the version of "Sospirava il mio core" from Book 3 included above, these are superb performances. The chosen pitch is a step lower than what many ensembles have chosen, but I very much like the lower tessitura: it gives the sound of the ensemble a depth and richness that few other groups in this repertoire can match. Longhini has also chosen to use only male voices, with countertenors taking the highest parts. This also works beautifully—the similarity in timbre allows the voices of Delitiae Musicae to blend in a very pleasing way. It's also historically justifiable: falsettists are known to have sung in sacred and secular ensembles in the sixteenth and seventeenth centuries.
A choice that seems less historically justifiable to me is Longhini's decision to add continuo parts to some of the madrigals in Books I - IV. As far as I'm aware Gesualdo gave no indication that his madrigals should be performed with instruments. While the accompaniment is limited to a discreet harpsichord, in my view it's an unnecessary addition.
But the added harpsichord is a minor issue when the vocal performances are this focused and assured. Longhini's tempi are measured, and this makes the dissonances just a bit more apparent without requiring the singers to give them extra emphasis.
Many thanks to the dear friend who gave me this collection recently as a birthday present, thinking (correctly) that I would listen to it obsessively; for the last several weeks there's been at least one disc, and sometimes nothing but Gesualdo, in my CD changer. I recommend it highly.
1. This account is taken from the depositions of witnesses to the murders quoted in Watkins, Glenn. Gesualdo: The man and his music, Second edition. Oxford University Press, 1991, pp. 15-23.
2. Quoted in Watkins, p. 83.
3. Watkins, p. 166.
4. Burney, Charles. A general history of music from the earliest ages to the present period, Volume the second, with critical and historical notes by Frank Mercer. Dover, 1957, p. 181.
5. Watkins, pp. ix-xi.