1.) All music that is to be licensed is copyrighted materials. Whether they advertise themselves as “royalty-free”, the music does not fall into the public domain. You need to agree to the license or the terms of conditions before you can commercially exploit the music.

2.) The length or term of copyright is not fixed by a number of years. Instead it depends on a variety of factors such as the number of authors, on what country the author lives or where the work was first published and the type of work. Source: http://en.wikipedia.org/wiki/Copyright_term and http://www.nolo.com/legal-encyclopedia/checklist-29483.html. These different varieties can further confuse any persons interested in knowing if the work is a “public-domain” material.

3.) You can reuse public domain music or incorporate it with your composition without requiring a license. Some even popular hit songs are based on the arrangement and structure of public domain music.

4.) A good example of public domain music are classical works made by Beethoven, Mozart, Bach and all those classical composers for which the copyright already expires.

5.) As a short and easy definition, music will fall into public domain if the term of copyright expires.

This can start to sound complicated because of the variety of factors involved above that determines the duration of copyright. The term of copyright which is an important indicator whether the music now belongs to public domain varies. However below are minimum and maximum terms based on this document:

1.) Life of the author + 50 years;
2.) Life of the author + 70 years

So if the author lives for around 90 years, the entire life of copyright has a minimum of 90+50 or 140 years and a maximum of around 90+70 = 160 years. This is one of the main reasons why most classical music works (done by Beethoven, Mozart, etc) are now belonging to public domain. The authors are long dead + 50 or 70 years after their deaths. Be careful when using“alleged” public domain music because it can get you in a legal trouble with the original authors. For example a song “All by myself” has been written by Eric Carmen with some lines and melodies borrowed from Sergei Rachmaninoff’s Piano Concerto No. 2 in C minor. At first, Eric thought the music was already in the public domain but it was not. The author/successors later claimed it when the song became highly popular. As a result, Eric Carmen made an agreement with the original authors. So let’s asked again, when does music fall into the public domain? Below are the suggestions which help you find a more accurate answer than relying on assumptions:

1.) You need a strong documented/legal proof that the music already exceeds the life of the copyright. In this case, consider using the worst scenario (life of the author + 70 years). Contact the copyright office and asked for documents. Of course prepare to spend for some research work.