The art that was created during the High Renaissance focused on reviving and improving the Classical principals, creating a naturalistic view of the human body and the importance of an educated artist. Works such as David were meant to show the Classical image of the body and told a Classical story in a new way. Several art works, including School of Athens by Raphael and Venus of Urbino by Titian, presented the topic of depicting the nude human body in a naturalistic light. During this time, it was also important for artist to know what had come before them, so they could produce it better.
As the times changed so did the art work and after the High Renaissance came the movement known as Mannerism. This movement focused on elongated and disproportionate bodies, contortion the body into twisted positions and the value of technical expertise. The painting of Madonna of the Long Neck by Parmigianino is a perfect example of Mannerism art. Madonna and child are both depicted with suck disproportion that the audience wonders how the baby stays on her lap. The ladies that surround her as well have such elongated legs that they become a distraction.
During both movements Michelangelo was a working artist who really flowed into this change with his works. The Sistine Chapel is a great example of the values that the High Renaissance art possessed. As as artist he would have to be educated in religion, philosophy and what other artist before him did in order to create the images and stories from the Bible onto the ceiling. He was also so interested in the male nude body that he constantly tried to rework and recreate positions that the body could be presented in. As time went on he took this passion for the body and really pushed it into a whole new level during Mannerism. In his Night and Day sculptures he "beefs up" the body so that one can see all the muscles, puts the body into these twisted and unrealistic positions and elongated certain body parts so that they become disproportionate.
These two movements truly valued very different aspects of art and art making but both valued a sense of artistic expertise and knoweldge of other artist and historical and biblical events.