Ask the iTunes Guy: Missing audio files, classical music, and .m4a files

You've got some music files on your Mac, and they all look alike in the Finder. If you want to find which ones are AAC files and which are Apple Lossless, what do you do Well, I've got the answer. I also discuss the Case of the Missing Audio Files, and look at some possible ways to view classical music in iTunes.

What kind of file is this

Q: How can I tell if a file with an .m4a extension is a lossy AAC file or an Apple Lossless file

It's a bit annoying that Apple uses the same file extension for both lossy and lossless files, especially because AAC is part of the MP4 specification, and Apple Lossless is not.

If you're looking at a file in the Finder, it's not that easy to tell one from the other. The Kind that the Finder shows for both files is Apple MPEG-4 Audio. In the screenshot to the right, you can't tell that the file on the leftJohn Foxx's "No One Driving"is an AAC file, and that Yes's "I've Seen All Good People" is lossless. You can see the difference in the file size, which is a good indicator, but you need to mentally calculate the ratio of the size and duration.

Within iTunes, you can tell which files are lossless in other ways, such as by displaying the Bit Rate column in list views. Lossless files have higher bit rates, generally above the highest AAC bit rate of 320 kbps. You can also make a smart playlist to find all your Apple Lossless files. Use the condition Kind Contains Apple Lossless.

There's one more way you can tell these files apart: that involves using Terminal. There's a little-known command called afinfo that gives you a lot of information about a music file. Open Terminal (it's in your /Applications/Utilities folder), type afinfo, then a space, and then drag an audio file from the Finder to the Terminal window. Press Return, and Terminal will display information about the file. Near the top, you'll see something like this:

Data format: 2 ch, 44100 Hz, 'alac' (0x00000001) from 16-bit source, 4096 frames/packet

In the last line, you can see that the file is alac, or Apple Lossless Audio Codec.

A lossy, AAC file will display this:

Data format: 2 ch, 44100 Hz, 'aac ' (0x00000000) 0 bits/channel, 0 bytes/packet, 1024 frames/packet, 0 bytes/frame

Where did my files go

Q: Somehow, over time, hundreds of files (from a library of maybe 5000 songs) have been deleted from my iTunes library folder. I have scores of empty folders that once contained all the tracks of albums. For other albums, just one, two or more files are gone. I back these files up daily, but the problem is that I'm not aware when files suddenly disappear, so the backups often delete files in order to conform with what is in the (new) iTunes library. I don't see anything that links those files that are lost; it seems entirely random. What can I do about this

I've been getting a lot of questions about this recently. This has happened to me too. It started some time last year, perhaps just after iTunes 12 was released. I back up my music with Time Machine, as well as with a standard copy, and Time Machine keeps older versions than those in my most recent full-disk backup. I have no idea why iTunes deletes files, and I wish Apple could figure this one out. In the meantime, I'd recommend using Time Machine to make sure you don't lose anything.

Viewing classical albums

Q: I would like to use iTunes for my classical music collection, displaying music sorted by composer. The album, in my case a symphony or string quartet, for example, is then shown with all its "songs" (movements) which takes up too much space. Is there a way to list the albums without displaying the songs

It sounds like you're using this type of view for your music:

For the albums above, many of which contain short works, it makes sense for each track to be listed. But if you tag your albums per work--for example, a recording of Mahler's 3rd symphony is an album--then this view isn't ideal.

If you do want to sort by composer, then you don't have many choices. You can't change the way iTunes displays content within each of Songs, Artists, Composers, and Genres view. You could use Albums view, which only shows album artwork (or gray squares with musical notes, if your music doesn't have artwork).

But when you click an album to play it, iTunes expands that album and displays its tracks.

You can't always get what you want. Sometimes you have to bend to iTunes' will.

Have questions of your own for the iTunes Guy Send them along for his consideration.


Kirk McElhearn

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