The early abbeys were small communities with some 10 or 20 monks in each. But later they grew in size and some abbeys had hundreds of members. They . had big buildings and large estates. They also built schools, colleges, and hospitals around the abbeys. These abbeys have given great contributions in the spheres of Art and Knowledge. Abbot Hildegard was a gifted musician. The monks played a big role in the common collective prayers of the Congregations. They had kept copies of manuscripts of great books. This helped the growth of knowledge.