How do music files get corrupted.

It's because hard drives are finicky, analog beasts: they use magnetism to store data, and over time either the magnetism weakens, or it's disrupted by -- I kid you not! -- cosmic rays, or the aluminum platter on which the magnetic charge is stored developers a barely perceptible fault. This is why backups are so critical.

It's nothing specific about music files either; my parents lost several hundred photos of their grandkids a couple of years back because of random hard disk corruption. Trust me, if your music is becoming corrupted, then so are other files. You just don't know it yet because you don't access the other files as often.

And just to be clear: optical media (CDs and DVDs) fail too. All the time! Usually it's because the aluminum under the clear plastic layer has begun to oxidize due to tiny holes in the plastic. Commercially-burned media are safer, but I've even had DVDs I owned less than a year, without a single scratch, spontaneously go bad.

A program called DiskWarrior can be a great help getting files back, but at $99, it's pricey. Worth it, in my opinion, but get yourself an external backup drive first. It costs about the same, $99 or so.

this is not necessarily the case, I had an itunes library go bad on me. I noticed the corrupt files on my ipod, they were either skipping real bad or sounded like there was some crazy modulation filter applie. Anyways, i went to iTunes and the files were bad there, so I played them in WMP, also bad, so obviously it was a file issue, BUT, what was the source of the corruption.......also, this happened ONLY to mp3s, no other audio file.......so i had backups and copied the bad files from a dvd and played them in WMP, files were good, then i import them to iTunes, and the files are crap again, so I tried just adding to library, still bad. So the file was fine before, once iTunes touched it, the file went bad, I **** you not. So I uninstalled iTunes from my PC, downloaded the newest version and reinstalled, same problems, so i continued trying with a different version, and making sure all registry entries were cleared before installing etc. NOTHING, so in the end i had to start using Winamp and all those files have not since caused me problems. So NO, it does not have to be hard drive issues, assess your own situation and you should be able to figure out if it is your HDD. My problem seemed to be iTunes library corrupting my metadata. However, I could never get it to work. I am glad to say I have since abandoned my PC and bought a new iMac on which i once again happily running iTunes with all the same audio files as before

You've got flaky hardware... Thats about the only explanation.

I would immediately run the 'Verify' function from disk utility to start with.

I have a larger number of corrupt files on my iphone. They skip.. it's VERY annoying.
Unfortunatly on iTunes they are also corrupt.

I have time machine, but the iTunes interface doesn't do a good job of keeping track of my music backups.

Also... its my opinion that the software should be maintaining checksums of all this data.
iTunes software should generate a checksum when the files are purchased, and if you have the correct checksum, you should be able to "refresh" the file with a correct update. This checksum could be encrypted or whatever to protect DRM, but dammm I paid $ for all these files and I can't copy them easily myself, so have to rely on iTunes to manage it.

ARRGGGHHHH!!!

? this is not true.

If hard drives were as finicky as you describe... nothing on your machine would be stable.
It would be like running Windows Vista. (For those who are running Windows Vista... I apologize)
I have a couple of those machines myself... Windows 7 "The Apology" is due out soon, we shall see how well MSoft manages to do with that.

I suspect it's a software issue. Itunes makes periodic "backups" and also "syncs" these files. I suspect (but can not prove), that the data transmission process during backups of the iPhone doesn't do any error checking of the data transfer... and this is where the files get corrupt. Alternately, it could be a problem with the FLASH memory on the iPhone. This is newer technology than hard drive technology.

I've had this problem before, done a restore from a backup and was fine...

However, iTunes periodicly backs up the music on my phone, so I'm not sure I will be able to recover a 100% clean set of files... what a data management nightmare.

The problem as I can see it, is that this problem is common, and when it occurs large numbers of your expensive files are at risk(in my case all files purchased on iTunes) .

I disagree.
(again).

I suspect it is in data transfer through the USB port, and it might be occurring when iTunes does a "backup" of your files or when a "sync" occurs. I suspect there is no error checking for lost bits.

On the other hand... running a verify is always a good idea to rule out a hardware malfunction.

I've had this problem both with my Laptop PC running Windows XP & iTunes, and now with my iMac running iTunes. The only common factor is the sync/backup process (this is my third "physical" iPhone due to other syncing issues).

Its frustrating enough that I'm considering giving up on iTunes this is the second time since April that I've had this "skipping" issue and had to "restore" the phone from a earlier backup.

I have now hundreds of corrupt Apple Lossless files in iTunes. I believe it happened acutely, perhaps when goiung from version 8 to 9? I do not sync but one way, from iTunes to an NAS server, never the reverse, so I cannot exlain these songs getting corrupted by anything but a software glitch. Everything else on my Mac works fine.

When I look at the files, the icon for the corrupted ones is just a black box instead of the box with the little musical note in it, or the actual album cover. Is this an indication that the ID tag is corrupted?

But my question is, is there any reasonable way to find these corrupted files as I have about 20,000 songs in iTunes and cannot of course start going through them one by one.

Does someone want to upload one of these corrupted files to mediafire or mobileme so I can take a look at it?

Unfortunately I couldn't really gather anything we didn't already know from that file.

I will say that I don't see how iTunes could cause this sort of problem. I have encountered situations in which iTunes may choke on certain ID3 tags in an MP3, but this is very different.

Basically there are just missing samples.. IE: The data isn't there anymore. iTunes really has no mans to cause something like this by itself, there has to be some underlying issue.

Also, you folks that think this is happening during the syncing process. Files are only copied from a mobile device when they are downloaded on the device from the iTMS. When you sync up your device the play/skip count and date are retrieved from the database on the device. No files are being moved around in this process.

Those of you who are having these issues... how were the files moved to your local drive? francisc, I noticed that the file you uploaded is very old. It was encoded with iTunes 7. Surely this files has moved from one computer to another at some point? Even though you may not have any issues on your current system, corruption of the file could have occured on a previous system or when it was copied to an external drive, etc.

Those of you who are experiencing this... Have you tried running any kind of disk verification yet? Thats really some key data.

Message was edited by: KelchM

iTunes does no such backup of your files. IE: iTunes never copies music files from your phone back to iTunes. The only exception to this is if you download something from the iTMS on the touch/iPhone.

You say you have experienced this on two computers. Are the files with issues common to both computers? How are you moving the files to each system?

It all comes down to this.. there are many points along the line where one piece of bad gear could corrupt some files. You might not notice this problem until much later (afterall, the bigger the library the less likelihood of arriving upon one of these corrupt files)...

Message was edited by: KelchM