Most types of music can be public domain music, as long as the music was created within a specific period. Sometimes there are references to music like “public domain jazz,” MP3, or iPod® public domain songs. Public domain jazz means jazz compositions that have been around long enough to enter the public domain. MP3 and iPod® public domain music refers to songs in the public domain available to be played on those particular kinds of media players. Most classical music is in the public domain, but more recent music types such as "rap" and some recorded music are not.
All copyrighted creative works at some point enter the public domain, which means they can be used by anyone. In general, if the creator is no longer living and seventy-five years have passed since copyright protection was obtained or one-hundred years has passed since the work was created, the music enters the public domain. However, under US laws enacted specifically to protect music, the work must have been created in 1922 or earlier to be considered in the public domain. In most other countries, it is seventy years after the author’s death. In Canada, it is the life of the author plus fifty years.
Public domain music includes the original sheet music. Additionally, a person may create her own arrangement or “remake” of a public domain song. This new arrangement can then be copyrighted by its creator. The prevalence of new arrangements of public domain songs can sometimes make it difficult to determine which version is the one actually in the public domain. In the US, sheet music with a copyright date of 1922 or earlier is proof that the song is in the public domain.
Music sound recordings are copyrighted separately from the musical arrangement itself and may not be part of the public domain. However, music recordings not in the public domain can be licensed for commercial use. It can also be obtained “copyright free” for personal non-commercial use.
In the US, some protected music is treated like public domain music under the “fair use doctrine.” Fair use means that copyrighted work can be used without payment under certain conditions. These include writing critical essays about musical works, classroom instruction about the cultural or musical relevance of a composition, research, and other non-commercial uses. Fair use requires that the user not alter the accessibility or value of the work for those who have paid royalty or other fees to use the work.