The deliberate induction of male hypogonadism by castration was practised from ancient times for various reasons. The Bible (Matthew 19, 12) states "there are eunuchs which were made eunuchs by men: and there are eunuchs which made themselves eunuchs for the kingdom of heaven's sake". The latter reference to the desirability of celibacy and chastity was taken only too literally by some early theologians (eg, Origen, c185-254), who castrated themselves for their religious beliefs. In countries of the Middle East and Far East it was most often done to provide eunuchs as guardians of the harems, and the practice persisted until the present century; the last eunuch of the Chinese imperial court died as recently as December, 1996. But the most intriguing reasons for prepubertal castration was to be found in Italy, where from the end of the 16th century it was carried out to preserve the male unbroken voice into adult life. In an age when cruelty and barbaric punishments were common, its popularity was such that for a period during the 18th century the voice of the castrato dominated opera throughout most of western Europe. Effect of testicular secretion on laryngeal development During puberty, sexual dimorphism of the larynx becomes obvious in the lower pitch and greater power of the male voice. Under the influence of increasing secretion of testosterone, or more probably its metabolite dihydrotestosterone, the total length of the male vocal cords grows from a prepubertal mean value of 17·35 mm to 28·92 mm in the adult, an increase of 63%, whereas female vocal cords increase by only 34% (from a mean of 17·31 mm to 21·47 mm). Testosterone initially produces oedema and vascular injection of the vocal cords, followed by a permanent thickening due to the accumulation of collagenous and elastic tissue. 2 These changes contribute further to the lowering of vocal pitch. From prepuberty to adulthood there is an increase in the anteroposterior length of the thyroid cartilage over three times greater in the male than in the female, giving rise to the well-recognised male "Adam's apple", and there is a two to three times greater increase in the weight of the thyroid, cricoid, and arytenoid cartilages. 1 Specific hormone receptors for dihydrotestosterone have been identified in most tissues of the male larynx, 3 and oestrogen receptors also have been found in the non-human primate larynx, 4 but whether oestradiol has a role in the smaller growth of the human female larynx is uncertain. In both sexes the increased somatic growth that occurs at puberty is brought about by growth hormone and other growth factors as well as by the genetic influence of the X and Y chromosomes. 5,6 This generalised growth results in enlargement of the pharynx, oral cavity, skull sinuses, and thoracic cavity, leading to the characteristic resonance and power of the adult voice compared with that of the child. Effect of castration on the male voice Removal of the testes results in the absence of male-type growth of the larynx. In the only recorded post-mortem examination of a castrato the dimensions of the larynx were strikingly small, with the vocal cords the length of a female high soprano. However, in a castrato somatic growth continued unhindered, resulting in a voice very different from that of the prepubertal boy. Although there was the high pitch of the child, soprano, or contralto, it was associated with fully grown resonating chambers provided by the pharynx and oral cavity as well as an adult thoracic capacity, made even more effective by intensive voice training. Yet although the pitch may have been similar to that of a female, the timbre of the voice was different. A contemporary critic described the castrato sound as being "as clear and penetrating as that of choirboys but a great deal louder with something dry and sour about it yet brilliant, light, full of impact". 8 Physical appearance of the castrati The manner in which the castrati appeared to their audiences can be judged from our clinical experience of eunuchoidism due to spontaneous primary hypogonadism. A tallness of stature, which was unusual in the 18th century, was commented upon by contemporary writers and was due to failure of the epiphyses to close at puberty, thereby allowing the unopposed action of growth hormone and other growth factors. There was a smooth pale skin, with, later in life, fine wrinkles around the eyes, no beard, plentiful scalp hair, a tendency to obesity, rounding of the hips, and narrowness of the shoulders; the pitch of the speaking voice was similar to that of a female. The intellect of a hypogonadal male is not impaired, but there may be feelings of inferiority and low sense of achievement. These inadequacies would not be expected to apply to the successful singers, but the mental condition of those who did not make the grade can be imagined. The effect of castration on lifespan has been debated. In a small study I did on 25 documented castrato singers born between 1610 and 1762 the mean lifespan was 65·1 years (SD 12·1) and was similar to that of 25 intact male singers born between 1605 and 1764 who lived a mean of 64·9 years (13·1) (unpublished). The relative longevity for this period may be explained by the fact that both groups lived fairly cosseted lives. The rise of the castrati Eunuchs had probably been singing in the Eastern church since early times, but the impetus for producing the castrato voice in western Europe came from the Church of Rome in the later 16th century. The development of complex polyphonic church music, with the elaborate ornamentation much favoured at this time, required voices in the higher register; for this purpose the Papal church choir had used boys and adult male falsettists, mostly imported from Spain, since there was a Papal injunction against women singing in public. But there were disadvantages in the use of children's voices because of their lack of power and their short-lived nature, while the sound of the falsetto was regarded as being inferior to that of the castrato. There is mention of a castrato in a Roman Church choir as early as 1553, but the first official announcement was in 1589 when Pope Sixtus V issued a Bull 9 providing for the inclusion of four eunuchs in the choir of St Peter's, Rome. Although the Sistine Chapel was for the private worship of the Pope, and therefore its constitution did not bind the Church as a whole, the practice spread rapidly so that by 1640 castrati were members of all the main choirs of Italy, and they continued to take their place in the Papal chapel for over three centuries. This widespread use of the castrato was extraordinary since it ran flatly against the Church's own canon law in which it was explicitly stated that deliberate amputations of any part of the human body were unlawful except when the whole body could not be saved in any other way. Some theologians opposed the practice,9 but generally the Church came to tolerate it on the grounds that the music so produced was for the honour of God, and such was the perceived need of the chapel choirs for the castrato voice that, hypocritically, the Church turned a blind eye to how or where in Italy the mutilation was done. The second, and even greater, cause for the rise of the castrato was the coming of opera to the Italian musical scene early in the 17th century. Opera arose from the festive musical entertainments of the Renaissance Florentine court, and the first opera of importance, Orfeo (1607), resulted from the genius of Monteverdi in Mantua. The new musical drama spread rapidly to the main cities of Italy, where the opening of public opera houses, the first being in Venice in 1637, provided centres of entertainment, not just for the upper classes but for the general population. Initially, the most professional singers were found in church choirs so that it was natural that their castrati took operatic as well as religious roles. Later, when, outside the Papal States, women did take to the stage, many people still preferred the better-trained voice of the castrato in female roles, and the ever increasing demand by theatre audiences for castrato soloists meant that the paths of those singing in the choirs and the operas became separate. The continuing development of opera seria with its stylised plots involving legendary figures and gods lent itself especially to the unreal sound of the castrato voice even in the roles of heroic male characters. The rise and fall of the castrato closely paralleled the popularity of opera seria, reaching its peak in the middle of the 18th century. The making of a castrato The usual age for castration was between 7 and 9 years. A contemporary treatise on the subject entitled "Eunuchism Display'd" published in 1718 by someone who styles himself as "a man of honour", 10 describes the various methods that were used. The least mutilating procedure was to sever the spermatic cords, after which the testes atrophied or in his words "grow lank and flabby till at last they dry up". In another method the boy was first put into a warm bath to make the testes more tractable. The author continues: "Some small time after they pressed the Jugular Veins which made the Party so stupid and insensible that he fell into a kind of Apoplexy and then the action would be performed with scarce any Pain at all to the Patient". Presumably bilateral pressure on the carotid vessels caused temporary loss of consciousness. Or again: "Sometimes they used to give a certain quantity of Opium to Persons designed for Castration whom they cut while they were in their dead Sleep and took from them those Parts which Nature took so great care to form; but it was observed that most of those who had been cut after this manner died by this Narcotick. It was thought more advisable to practise the Method just mentioned". In addition to the hazards of giving uncertain quantities of opium to a child there must also have been an unspecified mortality from haemorrhage and sepsis. It appears, however, that total removal of all the external genitalia, as in the case of Chinese eunuchs, was never done. Since the mutilating operation was illegal (despite the Church's employment of eunuchs in their choirs), the identity of the surgeons and where they came from were deliberately kept vague. All kinds of euphemisms were used to justify the existence of a particular castrato, such as disease of the testes or accidental injury--being gored by a wild boar was a common reason. During his tour through Italy in 1770 the English musicologist Charles Burney made extensive inquiries about the operation in Milan, Bologna, Venice, Naples, and Rome and received a complete denial in every place. 11 However, on another occasion when he was travelling in Germany, he came to Ludwigsburg where the ruler, the Duke of Württemberg, had in his choir 15 castrati and for their "vocal manufacture", as Burney called it, the Duke employed surgeons from Bologna as experts in the procedure. But the production of castrati almost always took place in Italy. There, because of the conspiracy of silence, it is not possible to get accurate information about those who carried out the operation, but in view of the large number of castrations during the 18th century (as many as 4000 each year 12 ) it is likely that, as well as surgeons, unqualified practitioners such as village barbers were involved. The boys nearly all came from poor families in various parts of the country, and it seems that their social background often provided the reason for their castration. Their fathers permitted the operation in the hope that the fame and fortune achieved by being a great castrato would come to them and their poverty-stricken families. Unfortunately, despite attempts to assess a boy's quality of voice before the operation, there must have been thousands of children who were castrated and never reached the top grade. Only a very small number progressed to the great opera houses, others into the best choirs, and those of lesser ability into ordinary church choirs, but, driven by parental greed, there were probably many whose mutilation was to no purpose. In 1770, Burney was saying on his visit to Italy that all the musici (castrati) in the churches at the time were made up of the refuse of the opera houses. 11 Boys who showed vocal aptitude were apprenticed to a singing master or entered a conservatorio to embark upon long intensive voice training lasting up to 10 years, when attention was given to their vocal technique and, particularly, their breath control. However, although the best soprano castrati were capable of great vocal range, rising to above high C, it was the voluptuous sensuous sound they gave to the lower notes that particularly entranced 18th century audiences. 13 The great castrati The castrati with the finest voices became operatic idols. In the first half of the 18th century, opera seria had spread from the great operatic centres of Naples, Venice, and Rome to many European cities, including London, where the top castrati were regarded as international stars, just as famous singers are today, and, similarly, they were able to command enormous fees. In 1764, when the Mozart family was in London, Giovanni Manzuoli (c 1772-82), a renowned castrato from Florence, arrived to open the opera season and, according to Leopold Mozart, he was being paid £1500 for coming as well as receiving the very large sum of 1000 guineas for a single benefit performance. 14 The most famous castrato of all was Carlo Broschi (1705-82), known as Farinelli, who had a legendary voice spanning over three octaves, from C3 (131 Hz) to D6 (1175 Hz), 15 and thoracic development such that he could hold a note for a whole minute without taking breath. Contemporary critics speak ecstatically about Farinellli. Burney wrote in his General History of Music (c1776-89) "No vocal performer of the present century has been more unanimously allowed by professional critics as well as general celebrity to have been gifted with a voice of such uncommon power, sweetness, extent, and agility as Carlo Broschi, called Farinelli". 16 Farinelli took London audiences by storm, one Englishwoman of fashion being so carried away during his performance that she exclaimed, "One God, one Farinelli!", 17 an acclamation satirised by Hogarth in The Rake's Progress. At the height of his career at the age of 32, Farinelli was invited to Madrid by the Queen of Spain to sing to her husband Philip V who was suffering from what now appear to be schizophrenic episodes. His singing seemed to ameliorate the King's condition--an early example of music therapy--and he became indispensable to the Spanish Royal Family for the following 20 years. London was fascinated by the castrato visitors from Italy; one who became resident in England was Giusto Tenducci (c 1735-90). He became friendly with Mozart while he was in London, and his portrait was painted by Gainsborough. The feelings of his audience are described by Lydia Melford in Smollett's Humphrey Clinker when she says, after a visit to Ranelagh pleasure garden, "There I heard the famous Tenducci, a thing from Italy--it looks for all the world like a man, though they say it is not. The voice to be sure is neither man's nor woman's but it is more melodious than either; and it warbled so divinely that while I listened I really thought myself in paradise". 18 But it was not only their voices that intrigued 18th century opera goers. Some of the visiting castrati were also physically attractive to women. Although their sexual performance may have been deficient, some castrati maintained their libido (Tenducci actually married), and women were comforted by the fact that any dalliance would not result in embarrassing pregnancies. As Dryden the poet wrote, "There are those who in soft eunuchs place their bliss / And shun the scrubbing of a bearded kiss". 19 The decline of the castrati As the 18th century progressed the enthusiasm for opera seria waned and, consequently, the need for castrati became less, but they persisted to some extent in opera until the early part of the following century. The last major opera that featured a castrato was Meyerbeer's Il Crociato in Egitto with Giovanni Velluti (1781-1861), the last of the important operatic castrati. His final appearance on the London stage was in 1829, by which time audiences had begun to regard these curious individuals with disapproval. But in the Sistine Chapel of the Popes, the castrati continued to be members of the choir. There was a temporary halt when the Papal States came under the rule of Napoleon in 1808, but after his removal in 1815 they were revived and were not finally excluded from the Sistine Chapel until 1902. The last castrato in the Vatican was Alessandro Moreschi who died in 1922 at the age of 64, so he was probably castrated about1865. A 20th century authority on the castrati, Franz Haböck, knew Moreschi and describes his voice as being powerful, but pure and clear as crystal, with effortless breath control. 20 Moreschi, uniquely, made several gramophone recordings of his voice in 1902 and 1904, and although the recording technique was very deficient by modern standards they provide our only direct evidence of the sound of a castrato's singing voice. In recent years there has been a great interest in the baroque music of the 17th and 18th centuries, and the desire to reproduce, in modern terms, the voice of the castrato has led to the revival of the countertenor. Some of these artists are extremely good and doubtless they sing this music very well, but one cannot help but feel that the powerful unreal voices described by 18th century critics are not completely reproduced. Nevertheless, the curious attraction of that audience to the half male, half female voice is perhaps repeating itself with the modern approval of the countertenor; and, on a different plane of art, is not the clamour of young pop music fans for androgenous stars a manifestation of a similar taste? References Kahane JC. Growth of the human prepubertal and pubertal larynx. J Speech Hear Res 1982; 25: 446-55. Goldman JL, Salmon UJ. The effect of androgen therapy on the voice and vocal cords of adult women. Ann Oto-rhinol Laryngol 1942; 51: 961-68. Tuohimaa PT, Kallio S, Heinijoki J. Androgen receptors in laryngeal carcinoma. Acta Oto-laryngol (Stockholm) 1981; 91: 149-54. Aufdemorte TB, Sheridan PJ, Holt GR. 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