The love songs of Vidyapati, which describe the sensuous love story of Radha and Krishna, follow a long line of Vaishnav love poetry, popular in Eastern India, and include much celebrated poetry such as Jayadeva's Gita Govinda of the 12th century. This tradition which uses the language of physical love to describe spiritual love, was a reflection of a key turn in Hinduism, initiated by Ramanuja in the 11th century which advocated an individual self realization through direct love. Similar to the reformation in Christianity, this movement empowered the common man to realize God directly, without the intervention of learned priests. Part of the transformation was also a shift to local languages as opposed to the formal Sanskrit of the religious texts.
The songs he wrote as prayers to Lord Shiva are still sung in Mithila and form a rich tradition of sweet and lovely folk songs.
Folklore says that he was such a great devotee of Lord Shiva that the lord was really pleased with him. And once He decided to come to live in his house as a servant. As the servant He is said to have taken the name Ugna. At several places in the region, Lord Shiva is still worshipped by this name. It is said that the lord in form of servant had imposed a condition on Vidyapati that he could not disclose his identity to anyone else or else he would go away. When Vidyapati's wife was angry at her servant and started to beat him Vidyapati could not tolerate the same and asked his wife not to beat Lord Shiva himself and since then the lord disappeared and never was he seen again.

Source : Wikipedia (http://en.wikipedia.org/wiki/Vidyapati)