Why can I find a song in the public search, but not when I search to license it through Songfile®? Why can I license a song for some formats, but not others?

Certain publishers have authorized HFA to issue, on their behalf, limited quantify mechanical licenses. Publishers may not always authorize HFA to license their songs for all formats. Additionally, HFA may be able to transmit a Notice of Intention (NOI) to publishers who have registered claims to compositions but have not authorized HFA to issue limited quantity licenses. If the song is not available for licensing through Songfile®, you will need to contact the publisher directly to obtain a license.