Yes, the M4A is not so common to all users, but it can be easily opened with iTunes, QuickTime, some newer versions of Windows Media Player, etc. Songs with an M4A file extension usually include copyright protection, just like the one M4P files have. This type of file format can be found in iTunes Stores.
Due to a smaller sample block size of 120 or 128 samples, M4A files allow more precise details if needed, which is quite cool, don’t you think? Plus, it has larger block sizes in stationary signals, which are usually 1024 or 960.
