Joni Eareckson Tada is an American evangelical Christian author, radio host, artist, and founder of Joni and Friends, an organization "accelerating Christian ministry in the disability community".
A great read for a brief history and theology behind some beautiful hymns that have withstood the test of time. About 2-4, one or two page excerpts per hymn from various authors. Overall it’s a short, brief treatment but still beneficial as a light read.