Links to other sources of information
The chief source of information about Sacred Harp music is the American Fasola website.
The Sacred Harp Publishing Company website has masses of information about The Sacred Harp. Their newsletter is a wonderfoul source of articles on many aspects of this music.
For the background to shape-note singing in the UK and a Calendar of future singing events in the UK and beyond, see United Kingdom Sacred Harp and Shapenote Singing.
There are Sacred Harp and other shape note groups all over the UK and beyond, many of them with their own local web sites and Facebook pages which you can search for on line.