I would like to draw your attention to one recording only here: Beata Vergine, a compilation of early Italian baroque Marian pieces sung by the astonishing countertenor Philippe Jaroussky. "Love songs to the Queen of Heaven," one reviewer called this. Very true.
Despite the despicably ugly cover, the CD will introduce you to his voice, the sound and expressiveness of the male alto, and much new Marian music here by forgotten or otherwise unknown composers such as Rigatti, Grandi, Colonna, Caprioli, Legrenzi, and Mattioli.
It is the least splashy of all his available CDs but perhaps the most beautiful and sacred.
Here is a video to introduce the sound of Jaroussky's voice:
His other work shows off his talent for speed and articulation in the repertoire written for the castrato, the story of which is certainly one of the most peculiar in the history of sacred music. The Church had long discouraged the practice of making castrati but the Sistine Chapel continued to employ them throughout the 18th and 19th centuries. Their voices had the power of the male but the range of the female, and they were not only useful in a male-only choral setting but also highly revered by the public.
The problem with continuing to hire them, even as an act of charity, is that it set up a moral hazard. So long as there continued to be a market for their voices, poor families with boys with good voices would have the incentive to mutilate for professional purposes and social advance.
It was the famed Italian priest-musician Lorenzo Perosi who, during his tenure as director of the Sistine Chapel choir and the world's leading ecclesiastical composer, waged what was known as the "war on castrati" and had them all fired. At last, the moral hazard was over and the practice condemned centuries earlier came to an end.
One castato, however, made it into the recording age. His name was Alessandro Moreschi (1858-1922) and he was a long-time singer for the Sistine Chapel choir. The recording below was made in 1902. This was the end of an era in Church music, a chapter closed by Pius X before a new one opened that was led by the restoration of Gregorian chant and the publication of the Vatican Graduale in 1908.
Before you dismiss Moreschi's voice as ridiculous, consider that he was probably past his prime when he made it, and he was singing with the style of his times. He was thoroughly dedicated to his art and to the faith and to the institution of the Sistine chapel choir as it then existed.