Most are free-to-use (ie public domain or copyright-free) meaning the words can be copied and sung to at least one tune with no concerns about copyright or performance licensing. Many such hymns are old/traditional - but where possible a variety of styles / genres are included. A small selection of hymns that are still be copyright may also included where they are a particularly good for for the theme(s).
The third Sunday of Ordinary Time has also been nominated as the day to observe Sunday of the Word of God: Any hymns based directly on Scripture may be helpful to support this, and a list of hymns about The Word of God has been prepared.
Suggestions about other free-to-use hymns that could be included are welcome: leave a message in the Comments box near the bottom of the page.
