Will Fitzgerald and James N. Gingerich have set up an online publication of the 26th edition of the Harmonia Sacra. Click the link to go to it.
The Harmonia Sacra was first published in 1832 by Joseph Funk under the title A Compilation of Genuine Church Music. The online Harmonia Sacra presents the tunes in both seven-shape notes and four-shape notes. The seven shapes of the Harmonia Sacra are Funk's and not the "standard" Aiken shapes in most seven shape books. You will find various tune indices (by page, tune name, first line, etc.), Joseph Funk's rudiments of music and information about Harmonia Sacra singings.
Well done, guys.