Similarly, glees had not been especially singled out before this period, and their encouragement eventually led to the formation of clubs explicitly devoted to glees, starting in 1787 with the Glee Club in London and another at Harrow School. On the whole the glees stimulated by the prizes started with a clearly pastoral or abstract content and developed a style which separates them from the earlier part-songs published in catch collections. Catches on the other hand increasingly exploited the gaps revealed by rests which reveal hidden meanings from other lines, to the extent that many began to believe that this is the essence of the catch.