Michelangelo's most famous piece of sculpture is probably the Pieta of 1498-9. Art essays like to compare this with another religious piece of sculpture, the St. Matthew, which was executed in the first decade of the 16th century.
The Pieta is undoubtedly one of the great technical masterpieces of carved stone. It is all delicacy and precision and Michelangelo's most finished sculpture. The word "virtuosity" (which de Tolnay applies to it) must surely come to one's mind when one views this exquisitely crafted piece of sculpture.
The St. Matthew is an entirely different work. For one thing, it is unfinished; it was part of the work Michelangelo, did on the tomb of Julius II, work that, because it was never completed, caused Michelangelo great distress. Here we have a work not of elegance, but power, a work not of gentle sadness, but of the primitive suffering of the soul struggling in the too narrow envelope of the body.
The aesthetic beauty of the Pieta is something extraordinary and its technical perfection exemplifies one of the key aspects of Michelangelo's genius-his mastery of the various media in which he chose to work. One gets the impression from the Pieta that its creator could do anything with stone that he liked, that he had achieved a kind of confidence and authority with respect to technique that gave him the freedom to create anything he wished to create. Great virtuosos in any art form convey that sense of authority and mastery over the media that they make use of; within their realm they appear almost superhuman.