Salvation Army Tune Book

The Salvation Army Tunebook (2015) is available in two volumes (books).

Volume 1: 1-530 are for pieces which follow a set metre, allowing the different tunes to be used for the same lyrics
Volume 2: 531-958 are for pieces where the music is specifically written for the lyrics of the song

A US Review of the 2015 release can be found here.
A Canadian review of the 2015 release can be found here.

The Salvation Army Tunebook can be purchased from UK Trade: both Volume 1 and Volume 2.
There is also a mini size Solo Cornet part, softback only available here

For those interested in previous versions of the tune book, titles, indexes and comparison charts can be found at
There is also an online archival version of the original edition of the The Salvation Army Songbook (1911)