Charles Wesley wrote on a scale that is hard to take in, some thousands of hymns across fifty years, and the 1780 collection is a selection from that output rather than a survey of English hymnody. His characteristic method is to build a hymn out of scriptural phrase, so densely that a single stanza may allude to half a dozen passages, and to hold the whole together with a metre that carries a congregation forward rather than letting it dwell.
What that sounded like in the field was contentious at the time. Eighteenth century English parish worship largely meant metrical psalms, sung slowly and led by a clerk. Methodist singing was faster, louder, in parts, and done by everybody present, and critics of the movement said so as a complaint. John Wesley's Directions for Singing, printed in 1761 and still reproduced in Methodist hymnals, tell the singer to learn the tune, to sing all the words, to sing lustily and with a good courage, to take care not to bawl, and above all to keep with the congregation rather than running ahead of it. They read as the instructions of a man who had heard both the enthusiasm and the noise.
The collection travelled with the movement. Methodist missions carried it, the American connexions built their own books from it, and the Black Methodist denominations formed in the United States in the early nineteenth century took the Wesleyan repertory with them and developed it in their own directions. Every hymnal in that family is downstream of 1780.