How iTunes Works

iTunes compatibility in the realm of portable players is a bit of a quagmire, which is part of the reason why some people just avoid iTunes entirely. You can use the iTunes Mac software with, say, a Creative Nomad MP3 player (see iTunes for Mac OS X: Compatible Players for a complete list). But iTunes for Windows only supports the iPhone, iPad or iPod series -- if you connect a Creative Nomad to a Windows machine running iTunes, the software won't see it. And there's no version of iTunes for Linux machines, either. But there are ways around that -- just do a Google search for "iPod Linux hacks." What's more, Apple is no longer updating the compatible players list, which may suggest iTunes won't support new non-Apple players moving forward.

Since the introduction of the iPhone, Apple no longer provides iTunes support to new phones from other manufacturers. Apple's strategy is to convince consumers to purchase Apple products and use them with Apple services. The company doesn't make it easy for you to use iTunes with any non-Apple device. Some companies, such as Palm, tried to get around Apple's closed system only to be shut down in subsequent iTunes updates.

So iTunes (or at least the Mac version) does support other players besides the iPod. But here it gets even trickier: Older music you downloaded from the iTunes Store is protected by the Apple FairPlay digital rights management (DRM) format, which is a proprietary, protected AAC file format that Apple doesn't license to anybody. The only devices that can play those files are ones with the ability to decrypt the Apple DRM, which includes your computer running iTunes, an iPod, an iPad, an iPhone, an iTunes phone and your speakers connected to AirPort Express. (You can't play them on Roku's SoundBridge, because Apple licensed Roku the iTunes software minus the DRM decryption.)

To play iTunes Store files with DRM on a portable player besides an iPod, you have to first burn them to a CD or DVD as MP3 files. The DRM encoding doesn't make it to the disc. You then rip the now-unprotected files back into your iTunes library and download them to the player.Alternatively, you can repurchase songs at a reduced price to get the version without Fairplay. Songs purchased from the iTunes Store in the iTunes Plus format don't carry DRM, which means you won't have to go through this step.

So now we know which devices will and won't work with the iTunes software. Next, we'll find out what you can do with the software if you've got the right hardware (or the wrong hardware with the right hack).

Even if you never make a single purchase from the iTunes Store, you can still take advantage of the basic functions of iTunes. iTunes offers all of the features we've come to expect from a high-level jukebox media player:

In addition to the typical jukebox functions, iTunes offers some nice advanced features:

So that's what the software can do. In the next section, we'll find out how to get started with iTunes on your computer.

Here's an overview of the main iTunes interface (version 10) on a Windows machine (the Mac interface is almost identical).

There are really just a few steps to getting started with iTunes:

Here's our new playlist:

Once you've got a feel for the software, check out the Advanced tab and the Preferences and View Options areas under the Edit tab at the top of the screen. From here, you can ­play with some of the features like display settings, file-type conversion, burn speed, parental controls and podcast settings. And you might want to explore the built-in iTunes Store to add to your library of content. In the next section, we'll visit the iTunes Store.

At the iTunes Store, you can find millions of songs, thousands of audiobooks, thousands of music videos, tens of thousands of podcasts, feature films, TV shows, iPad, iPod and iPhone applications, and CD album art. All you do to get to the store is click a button in the main iTunes screen. You're not going through a Web browser -- the jukebox software is the user interface for the store.

Apple has deals with record labels for iTunes-exclusive music tracks from select artists. In addition to pure content, there are community-type functions like user-published reviews, ratings and playlists, and then there is the pop-culture headshaker that is the "celebrity playlist." These are lists of songs (with a little "buy song" button next to each track) reportedly assembled by stars like Quentin Tarantino, RuPaul and Lady GaGa. In case you're curious, Lady GaGa included songs like "Thriller" by Michael Jackson, "Blue Christmas" by Elvis Presley and "Radio Ga Ga" by Queen. She also included three of her own tunes on her list. There's also a podcast dedicated to celebrity playlists if you want to keep up with what the rich and famous listen to.

Here's a breakdown of the store content areas and what you can do there:

Music

 Music videos

Audiobooks

TV shows

Feature-length films

Podcasts

iPhone and iPod Applications

Movie Trailers

­In addition to browsing each content area, you can also perfo­rm a search. There's a search box on the main store page where you just enter a keyword, and iTunes returns matching results from all areas of the store. You can also perform a "power search" by song, artist, album, genre or composer. If you enter "Adam Sandler" in the "artist" field and choose "comedy" as the genre, you'll get a list of all of Adam Sandler's songs and albums available on iTunes. If your mother has set up parental controls to limit your access to explicit content, you'll see a lot fewer results than we did.

Apple also includes a link to free content available for iTunes. This can include samples from all the categories we've listed. Sometimes the free content is available for only a limited time so it's a good idea to check this section regularly if you're interested.

­To buy content, you need to set up an iTunes payment account. To set up an iTunes account, you provide a credit card number or PayPal account that you'll use for all of your purchases. You can also pay using an iTunes Allowance (sort of like a debit account, typically set up by parents for their kids) or by Music Card or gift certificate.

To make a purchase in the iTunes store, all you have to do is click the "Buy" button next to the song, video or app. Apple will charge your account and the download will begin. If you have to shut down your computer in the middle of your download, the process will continue once you reboot your computer and log into iTunes. It's important to create a backup of your iTunes library. Songs, videos and iPod games (not apps) can only be downloaded once per purchase. Apps are different -- once you purchase an app, you can download it again for free. You just have to use the same iTunes account as the one used to purchase the app the first time.

All purchases are accomplished via an SSL (Secure Socket Layer) connection that encrypts the data. Exchanges related to browsing content and sampling songs happens in simple HTTP (hypertext transfer protocol) through a proxy server, which is a lower level server that sits between your computer and the main iTunes Web servers. This cuts down on requests sent to the main system architecture. Here's what else we know about the store's technology infrastructure:

The iTunes Music Store is composed of XML-based pages, lots of them encrypted using 128-bit AES in CBC mode. AES-CBC is a type of symmetric-key encryption. AES ( for advanced encryption standard) basically takes a 128-bit block of code and reorganizes it into a 128-bit block of ciphertext using a particular key (an encryption algorithm). CBC (cipher block chaining) mode is a method of disguising any encryption patterns that might reveal the key. In CBC, what happens is sort of like a double-layer encryption scheme. During the encryption process, each consecutive, 128-bit block of unencrypted text (we'll call this the "original block") is XORed with the previous, already encrypted block of ciphertext to generate a 128-bit block of text that represents the original block. The "XOR" operation is a piece of computer code that returns values based on an "exclusive OR" formula -- for example, an XOR operation might state that if the first bit in the original block OR the first bit in the ciphertext block is "1" (but only one or the other), then the resulting value is "1." This "1" is now the first bit in the new, 128-bit "representational block." It is the representational block that will be encrypted using the key. In this way, if you were encrypting a page that had two consecutive, identical 128-bit blocks of code, they would end up as completely different blocks of ciphertext.

The same key is used to encrypt and decrypt the ciphertext -- that's the "symmetric" part of the process. Once each block is decrypted using the key, the XOR operation is reversed to generate the original block of text. See Cryptographic Algorithms and RFC 3602 to learn more about AES-CBC encryption.

As we already mentioned, the iTunes Store once used a proprietary encryption method called FairPlay for its digital rights management scheme. When you purchased a song, the file was encrypted as part of the download process. Next, we'll take a closer look at FairPlay and the controversy that surrounded it.

FairPlay was an Apple-proprietary encryption scheme that determined what users could do with a file once they downloaded it. FairPlay let you:

­To authorize a computer, all you had to do was to try to play a protected song on it. When you did, the computer generated a unique ID and sent it to the iTunes server, requesting authorization. If there were fewer than five authorizations on your account, the server added this unique ID to your account and sent back a decryption key to store on the computer. The key itself was encrypted so you couldn't just send it to someone else to use. This computer was then authorized to play FairPlay-protected songs registered to that account. The next time you clicked on a protected song, the iTunes software used the computer's authorized ID to decrypt the key and then used the key to decrypt the song. Newer tracks on the iTunes Store are free of FairPlay encryption, but the technology still works if you attempt to play an older encrypted track.

Most of the controversy surrounding FairPlay was about Apple's refusal to license it, not about the limitations it imposed -- as far as DRM schemes go, FairPlay wasn't overly restrictive. But since Apple didn't license FairPlay to anyone, you could only play a protected file using iTunes software, and you could only take it with you on an iPod, iPhone or an iTunes phone. By keeping FairPlay in-house, Apple effectively created a dependence loop between iTunes and iPod that some went so far as to call a monopoly on digital entertainment. In January 2005, one person filed a class-action lawsuit against Apple to this effect, claiming the company is violating federal anti-trust laws.

The other problem with FairPlay was that it created a Linux shut-out. Since protected songs will only play on iTunes, and iTunes is only compatible with Mac OS X and Windows XP or later, people who use the Linux operating system without running a virtual Windows machine can't buy content at the iTunes Store (actually, they can buy it -- they just can't play it). This led to an ongoing war between Linux hackers and Apple. The most famous example of this battle is the back-and-forth between a team of hackers led by "DVD Jon" Johansen (who cracked the DeCSS encryption on protected DVDs in 2002) and Apple programmers [source: Borland].

In January 2004, Johansen published a piece of code that disabled Apple's DRM scheme on the user end, allowing people to play FairPlay-protected files on a Linux machine. In March 2005, Johansen released a piece of software that disabled FairPlay on the Apple end, creating a glitch in the download process that stopped the encryption from being applied to a file. Just days later, Apple released a new version of the iTunes software that disabled this glitch. One day later, Johansen released another piece of code that recreated the glitch. And from there it went on in much the same vein.

The digital-media business has gotten a lot more complicated in the last decade. When file-sharing networks opened a gaping hole in the entertainment industry's ability to control the distribution of its content, a war broke out between copyright holders and consumers. The current manifestation of that war is DRM and DRM hacking. FairPlay was only one example of DRM -- many companies dealing with licensed digital content have adopted DRM schemes that limit what a consumer can do with legally purchased files. See How Digital Rights Management Works to learn more.

The fact is, working with the entertainment industry to license content is not a simple process. When Apple strikes a deal to sell licensed content, everybody wants a cut. As soon as iTunes started offering TV shows, Apple having struck deals with the TV networks that own those shows, the five entertainment-industry unions decided they needed a cut, too. So out of that $1.99-per-show charge, Apple is paying royalties to a whole lot of people. Subtract from that the cost of building and maintaining the iTunes technology infrastructure, paying credit-card fees and advertising the service, and it looks like Apple's iTunes Store is more of a marketing vehicle than a big revenue generator for the $8 billion company. In short: The iTunes Store helps sell iPods, iPhones and iPads.

The backlash against DRM didn't go unnoticed. In 2007, music publisher EMI announced it would sell unprotected music on iTunes. Any song from EMI would come without the FairPlay DRM. In early 2009, Apple announced that it was phasing out the FairPlay technology throughout the iTunes Store. Today, any song you purchase from iTunes shouldn't have any DRM technology associated with it. Older songs purchased during the FairPlay era still have DRM code. Apple allows users to upgrade to a non-DRM version of the song for 30 cents per song. Alternatively, you can burn the old music files to a CD, which removes the Fairplay DRM from the tracks. Then you can rip the songs back to iTunes.

The future of iTunes most certainly includes ongoing hacking wars. One can only wonder if Apple will release a version of iTunes for Linux, if only to eliminate the legitimate complaint that Linux people don't get to use the iTunes Store.

The introduction of the iPhone, iPad and the iPod touch have increased demand for the iTunes service, particularly the App Store. But it also means bad news for third-party products. Now that Apple is in the smartphone game, it no longer partners with other phone manufacturers to support iTunes implementation. From a business perspective this makes sense -- Apple is famous for trying to control as much of the customer experience as possible. By eliminating support of third-party products, Apple channels more customers to its own line of devices.

Apple also introduced Apple TV, a device that can play iTunes content on televisions. In September 2010, Apple unveiled some new features for Apple TV, including a partnership with Netflix. Apple is also expanding its content in unexpected directions like iTunesU -- a free service for universities to post lectures and other content for their students to download through the iTunes software. This prompted the University of Missouri's School of Journalism to include a new requirement for all incoming freshmen in 2009: every student must purchase an iPod touch or iPhone to access class materials [source: Rivera]. Though the word "requirement" may sound as though students will get themselves in trouble if they don't own an iPod or iPhone, the truth behind the arrangement is less extreme -- by making the devices a requirement, students could build the price of the device into their student financing requests. The school stated that students wouldn't be punished for not owning an Apple-branded product.

The next logical step might be to offer a similar service to businesses -- they could use iTunes to supply recorded meetings or training lectures to remote workers and frequent travelers. The future may see iTunes as standard software on office computers (and tiny iPod speakers embedded in the lapels of dark-blue suits everywhere).

For more information on iTunes, visit the links on the next page.