Though support for the feature was added to iTunes 7.4, iTunes Tagging remains one of the least-understood expansions of the iPod ecosystem—arguably, for good reason. Developed by Apple and implemented in new iPod speaker systems by companies such as Polk Audio and JBL, iTunes Tagging enables an HD Radio tuner to record information about the currently playing track, save it to an iPod, and let the iPod’s user easily find that track in the iTunes Store for purchase. Here’s a look at how iTunes Tagging works with Polk Audio’s new I-Sonic ES2, iTunes 7.6, and an iPod classic.

The process starts when you buy a device with an HD Radio tuner and the iTunes Tagging feature built in. For those who haven’t yet heard of HD Radio, an explanation is in order: HD Radio is an alternative to satellite radio, designed to provide terrestrial (land antenna-based) radio broadcasters with the ability to broadcast clearer digital signals and data similar to what XM and Sirius satellite services have been offering. Importantly, HD Radio has a couple of advantages. First, it’s subscription-free, and second, there isn’t a third “HD Radio dial” to scan for channels. Instead, analog stations are linked to one or more digital sub-channels, such that 107.9FM may now have 107.9-1 and 107.9-2 versions with HD Radio. For some reason, however, tuning of these stations isn’t entirely straightforward. The I-Sonic ES2 requires you to activate an HD Scan mode to look for these sub-channels, which is accomplished by hitting the seek button twice, then using the arrow buttons to move forward or backward through the AM or FM radio dial.


You might be surprised to realize that there are already stations broadcasting in HD Radio format: as of today, HD Radio’s web site showed 13 stations with 24 HD broadcasts in our immediate area. New York City showed 25 stations with 43 HD broadcasts, and Los Angeles had 37 stations with 58 HD broadcasts; additional channels are coming soon to each market. The vast majority of the HD Radio stations are FM channels; a minority are AM. In our local market, only one AM station offers an HD signal.


At least in the case of the I-Sonic ES2, you needn’t dock an iPod for either the HD Radio or the iTunes Tagging feature to work. The system is apparently capable of storing 50 tags in memory, awaiting docking with a compatible iPod. If you plug in an incompatible iPod—only the fifth-generation iPod, iPod classic, and third-generation iPod nano are Tagging-compatible—the system keeps storing tags until you connect an iPod that can transfer them.


The actual Tagging process is simple. Once you find an HD Radio station, the screen will display artist and track details, and illuminate a “tag” button underneath. Pressing the tag button leads to two additional screens.


First, the system stores the artist and track information in its own database. Next, if the right iPod is connected, it sends the tag over to the iPod. If not, it lets you know that it’s storing tag 1 or 2 of 50 in its own database, and subsequently sends the tagged information to a compatible iPod upon connection.


Our initial attempt to get iTunes to recognize tags on our iPod classic wasn’t successful, and the fault appears to have been with the ES2, which told us that it was sending tags to the iPod but apparently didn’t succeed in making the transfer. Consequently, iTunes saw nothing. But we re-connected the iPod to the ES2, the tags were re-sent, and on iTunes synchronization, a new iTunes Store-specific playlist appeared: “Tagged.” Inside were five tags, each with no album data, but a comment showing which station the songs had come from, and a blank where the price should be.


Most of the songs we’ve tested come up properly in iTunes, though the stations’ tag data doesn’t appear to have been ideally formatted for iTunes, or necessarily to match Apple’s database. Green Day’s Good Riddance was tagged by the station as Time of Your Life, and was located in a greatest hits album rather than the original on Nimrod; it’s unclear whether a given tag always brings you to the right version of a track, or just comes close. The latter appears most likely at this point.

There are also times when the ES2’s screen will go blank as it loses the track data, the HD Radio signal, or both. In situations like this, an attempt to use iTunes Tagging will most likely fail. We found that tags we tried to store under these conditions never showed up in iTunes at all, and it’s unclear whether the ES2 failed to store them, or whether iTunes couldn’t make anything of the tags it found. Manually re-acquiring the radio signal quickly is your best bet if you want to properly tag the current track. You may also have issues with tracks that have been re-tagged by the broadcaster to include scrolling messages; in this case, you’re better off just writing down the track details and looking them up in iTunes with a standard search.

Ultimately, iTunes Tagging’s obscurity is likely attributable to the high prices of HD Radio tuners, the lack of iPod family-wide compatibility, and the fact that the feature sidesteps what people would actually want—the ability to use iPods’ recording features to actually store songs—in favor of storing tags and pushing people towards purchases of iTunes Store music. But if this feature is something that interests you, it does work, albeit with a few small kinks.