M4A is an Apple lossless audio file, which is compressed with ALE (Apple Lossless Encoder). In addition, the M4A file uses ALAC, or Apple Lossless Audio Codec, which uses lossless compression, meaning you do not lose sound quality when you encode it into another audio format. You typically find an M4A file in the Apple iTunes store or on P2P programs such as FrostWire. If you suspect your M4A is corrupt, you can fix a broken M4A file to recover the audio file.
Download, install and start FileCure (see Resources).
Find the corrupted M4A that you want to fix on your PC.
Drag the M4A file onto the "FileCure" desktop icon to add the file to the program. Dragging your M4A file to the FileCure desktop icon bypasses the regular scanning process. Don't waste time scanning your entire hard drive. You already know what file on your PC is corrupted.
Click "Fix Now" to fix a broken M4A file.