Unprotected music tracks—those without digital rights management (DRM)—offer the advantage that you can legally using them without the same restrictions as other tracks. So, for example, you could incorporate them into personal projects such as slide shows and movies made with applications other than Apple’s. (Apple’s iLife suite can use protected iTunes tracks, but programs made by companies such as Adobe, for example, can’t.) But other than their unrestricted use, how do they compare sonically with the protected form? Most DRM-free music is encoded at a high bit rate and is therefore less compressed than standard digital music files. But will you be able to tell the difference between the protected and unprotected version (much less, those versions and one ripped directly from a CD in an uncompressed format)?
To find out, fellow Macworld editors and I conducted a little experiment. I ripped four tracks as uncompressed AIFF files from CDs—these songs are also available at the iTunes Store as standard files and iTunes Plus files: KT Tunstall’s “Black Horse and the Cherry Tree,” Libera’s “Far Away,” Terence Blanchard’s “Ghost of Betsy,” and “Wie Lieblich Sind Deine Wohnungen (Mässig Bewegt)” from the Berlin Philharmonic’s recording of the Brahms German Requiem. Then I purchased both the standard and iTunes Plus versions of each song from the iTunes Store. My colleagues Dan Frakes and Jonathan Seff did the same. We planted the three versions of each track on each of our fifth-generation iPods and conducted a blind listening test with the best headphones we each own. Our job was to see if we could tell the difference between the various versions of the tracks without knowing in advance which version we were hearing.
Our consensus opinion was that we couldn’t proclaim which was which. While using an A/B audio switch and two iPods playing the same track concurrently, I could tell, by quickly switching between the two iPods, that the AIFF file had a different character than the 128 Kbps protected AAC file. But without that switch, I couldn’t listen to a version and identify how it was encoded.
However, if you have an audio-engineer’s ears, you might be able to tell the difference. To find out, it’s worth your while to replicate our experiment. If you can tell one from the other and the difference between them displeases you, you have a better idea of where and how to shop. And if the difference isn’t noticeable (or noticeable enough to annoy you), congratulations—you’re a cheap audio date and can save 30 cents per track when you shop at the iTunes Store (as long as you’re OK with DRM).