If Audion cannot play such music files, it's my guess they are fake or deliberately corrupted files that are spammed around the network.
There are a lot of either fake or deliberately corrupt files being spammed onto the network. Catch a look at these: (1) Virus thread: Typical virus spam file sizes - Make a note of them (click on blue link to see) & also (2) mp3 Bit-Rates Versus File Sizes (click on link). Try to stay clear of particular sized files. And, if possible, try to compare bit-rates versus file-size for the same duration of the song.