Gospel music is in its simplest form a kind of Christian music (not that there are many hundreds of forms). Basically, it is religious music with lyrics that speak of Christianity and such. The significance, performance, creation and composition all draw from social context and culture thus the exact form of gospel music differs from location to location.
Gospel music performances can be for religious purposes, sometimes even aesthetic reasons and at other times for ceremonial reasons. While the main purpose of is Gospel music is to entertain, its roots are religious by definition. After all, the word “Gospel” refers to books written by the followers of Jesus. Conventional gospel music uses dominant vocals, strong harmony and religious lyrics. The practice started in the 17th century and can trace its root back to black oral recitations in the form of hymns and chants that are repeated. Back then the church was the stage and clapping of hands, foot stomping the choice of musical instruments. It still continues to be the tradition in some places though most churches now add musical instruments such as the saxophone, piano and even guitar to their gospels.
Some famous gospel lyricists or authors of all time include Philip Bliss, William Howard Doane, Charles H. Gabriel and even Fanny Crosby. By the time the radio came out in the 1920s, gospel audience saw a sudden growth in popularity which further strengthened soon after the Second World War. This was the time when concerts exclusively for gospel music became commonplace with auditoriums sold out across the US.
Thereafter, the singular niche of Gospel music began branching. Southern gospel, Gospel blues, Progressive southern gospels all became more commonplace. Major variations though include Celtic gospel that infuses together gospel music with a flair of the Celtic, popular mostly in Ireland. Likewise, UK referred to its version of Gospel as the Music of the African Diaspora.