The Copyright Clearance Center and BMI are good places to start. Both of these services work on behalf of copyright holders to distribute permissions/licenses.
You can also try the Copyright Catalog from the Library of Congress or the Virtual Card Catalog from the U.S. Copyright Office to find information for works that registered their copyright.
Works of unknown authorship, or works that have authors who cannot be tracked down, are considered orphan works. Orphan works are still copyrighted and using them involves a degree of risk. Whenever possible, substitute orphan works with a similar work for which copyright permission can be obtained.
You can contact the library for assistance with obtaining permission. For additional information, please see our Copyright Guide.
