This article explains what an M4P file is and how to play it on your computer or convert it to another audio format.
What is an MP4 file and how to open it in one minute?
A file with the file extension M4P is an iTunes Audio File, or sometimes called an iTunes Music Store Audio File. It is essentially just an AAC file that has been copy-protected using a proprietary DRM technology created by Apple.
This format is seen when downloading music from the iTunes Store. A similar file is M4A, which is also an iTunes audio file, but a file that is not copy-protected.
M4P files can be opened with Apple's iTunes. However, the computer you are using iTunes on must be authorized to play the file. To do this, log in to iTunes with the same account that was used to download the file.
