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The correct title of this article is iTunes. The initial letter is shown capitalized due to technical restrictions.
iTunes 7 icon

iTunes 7 under Mac OS X
Developer: Apple Computer
Latest release: 7.0.2 / October 31, 2006
OS: Mac OS X, Windows 2000 and Windows XP
Use: Media player
License: Proprietary

iTunes is a digital media player application, introduced by Apple Computer on January 10, 2001 at MacWorld Expo in San Francisco, for playing and organizing digital music and video files. The program is also an interface to manage the contents on Apple's popular iPod digital media players. Additionally, iTunes can connect to the iTunes Store (formerly known as the iTunes Music Store, or iTMS) in order to download purchased digital music, music videos, television shows, iPod games and feature length films. iTunes has gained and maintained a reputation for being easy to use while still providing many features for obtaining, organizing, and playing media. The program is available for free as a download off of the Apple website, bundled with all Mac computers and some iPods, and supplied with Mac OS X. It is also offered as part of Apple's iLife suite of multimedia applications.

iTunes, unlike other programs in the iLife suite, is supported on computers running on Mac OS X and Windows 2000 or greater. Apple has also developed a version which runs on mobile phones such as the Motorola ROKR, Motorola RAZR and Motorola SLVR (although as of October 2006 this version hasn't been updated to play songs purchased with iTunes 7.0). The program was initially developed on Mac OS 9, but support for the classic Mac OS was discontinued with the release of iTunes 3. There has been some success running iTunes under Crossover Office on Linux, which is a Wine variant.

iTunes originally had a brushed metal interface, but version 5.0 introduced a new, thinner interface commonly referred to as "plastic", "light metal" (as opposed to the heavier "Brushed Metal"), and "dark unified" (based on the Unified look from Mac OS X v10.4, but darker).


Users are able to organize their music into playlists, edit file information, record compact discs, copy files to a digital audio player, purchase music and videos through its built-in music store, download podcasts, back up songs onto a CD or DVD, run a visualizer to display graphical effects in time to the music, and encode music into a number of different audio formats.


In addition to static playlist support, iTunes supports 'Smart playlists'. Smart playlists are playlists that can be set to automatically update (live updating), (like a database query) based on a customized list of selection criteria. Different criteria can be entered to control many aspects of the playlist.

Playlists can be played randomly or sequentially. The "randomness" of the shuffle algorithm can be biased for or against playing multiple tracks from the same album or artists in sequence (a new feature in iTunes 5.0). Party Shuffle can also be biased towards selecting tracks with a higher star rating. With this bias enabled, each star rating increases the preference for that particular song about 4% over that of a one-star-less rated song. Unrated songs are the least likely to be played. Inter-star ratings are stored by iTunes, but only affect this feature in the range of zero to one star.

The Party Shuffle playlist is intended as a simple DJing aid. By default, it selects tracks randomly from other playlists or the library; users can override the automatic selections by deleting tracks (iTunes will choose new ones to replace them) or by adding their own via drag-and-drop or contextual menu. This allows a mixture of both preselected and random tracks in the same meta-playlist. The playlist Party Shuffle draws from can be changed on the fly; this will cause all randomly chosen tracks to disappear and be replaced.

Music library

iTunes keeps track of songs by creating a virtual library, allowing users to access and edit a song's attributes. These attributes, known as metadata, are stored in two library files.

The first is a binary file called iTunes Library (iTunes x Music Library in previous versions) that uses its own music library format. This both caches information such as artist and genre from the audio format's tag capabilities (for example the ID3 tag), and stores iTunes specific information such as play count and rating. This is the only one of the two files which iTunes reads.

The second file, called iTunes Music Library.xml, is refreshed whenever information in iTunes is changed. It uses an XML format, allowing developers to easily write applications that can access the library information (including play count, last played date, and rating, which are not standard fields in the ID3v2.3 format). Apple's own iDVD, iMovie, and iPhoto, and Freshly Squeezed Software's Rock Star are examples of applications that access the library.

For MP3 files, iTunes writes tags in Unicode ID3v2.2 by default, but converting them to ID3v2.3 and ID3v2.4 is possible via its "Advanced" > "Convert ID3 Tags" toolbar menu. If both ID3v2.x and ID3v1.x tags are in a file, iTunes ignores the ID3v1.x tags. AAC and Apple Lossless files support Unicode metadata, but it is not stored as ID3 tags.


To compensate for the lack of a physical CD, iTunes can print custom-made jewel case inserts as well as song lists and album lists. After burning a CD from a playlist, one can select that playlist and, by clicking File > Print, bring up a dialogue box with several print options. The user can choose to print either a single album cover (for purchased iTunes albums) or a compilation cover (for user-created playlists). iTunes then automatically sets up a template with art on one side and track titles on the other.


An iMix is a user-created playlist published in the iTunes Store. iMixes were first introduced in iTunes version 4.5. Anyone can create an iMix free of charge. iMixes are limited to 100 songs and support both music downloaded from the music store as well as music that has been imported from CDs (provided it is available on the iTunes Store). iMixes are public and searchable by any iTunes user. Users may also rate any iMix using a five-star system. iMixes are active for one year from their original published date. Users can publish their iTunes iMix to their blog, profile page or website.

Internet radio

iTunes 1.0 came with support for the Kerbango Internet radio tuner service, giving iTunes users a selection of some of the more popular online radio streams available. When Kerbango went out of business in 2001, Apple created its own Web radio service for use with iTunes 2.0 and later. As of February 2006, the iTunes radio service features around 300-400 distinct "radio stations" (with a total of over 700 streams, allowing for multiple bit rates), mostly in MP3 streaming format. Programming covers many genres of music and talk, including streams from online staples such as Radio Paradise, radioio, RauteMusik, Digitally Imported, Flashback Alternatives, and SomaFM as well as terrestrial stations such as KKJZ, WFMU, WMVY, and WRCT. iTunes also supports the .pls and .m3u stream file formats used by Winamp, enabling iTunes to access almost any stream using that format.

Apple no longer promotes the Internet radio feature, and no mention of it appears on the iTunes website. However, it remains in the QuickTime 7.0.4 & iTunes EULA used by iTunes

File format support

iTunes 7 can currently read, write, and convert between MP3, AIFF, WAV, Ogg Vorbis, MPEG-4, AAC, and Apple Lossless.

Conversion is done by changing the import format in 'preferences > advanced > import using...' dialog box. Once you change this setting to the file format you need, you can convert file formats under the 'advanced > convert to...' dialog box.

It can also play anything QuickTime can play (even some video formats), including Protected AAC files from the iTunes Store and audio books. In order to play other formats such as the Ogg-contained Vorbis or Speex codecs, iTunes requires the Xiph QuickTime Components to be installed. iTunes currently will not play back HE-AAC/aacPlus audio streams correctly. HE-AAC/aacPlus format files will play back as 22 kHz AAC files (effectively having no high end over 11 kHz).

There has been some criticism of the quality of Apple's MP3 encoder, with regards to variable bit rate encoding. In a January 2004 double-blind public listening test of six MP3 encoders encoding at 128 kbit/s, conducted by Roberto Amorim, the iTunes MP3 VBR encoder came last. The author has later acknowledged that there were serious issues with how iTunes was tested.

The Windows version of iTunes can automatically convert unprotected WMA (including version 9) files to other audio formats, but it does not support direct playback or encoding of WMA format.

Sound processing

iTunes includes sound processing features, such as equalization and "sound enhancement" ("sound improvement" in some languages). There is also a feature called "Sound Check" which automatically adjusts the playback volume of all songs to the same level. Like "sound enhancement", this can be turned on in the 'Playback' section of iTunes' preferences.

Music sharing

iTunes Library songs can be shared over a local network using the closed, proprietary Digital Audio Access Protocol (DAAP), created by Apple for this purpose. DAAP relies on the Bonjour network service discovery framework – Apple's implementation of the Zeroconf open network standard. The DAAP specification has not been published by Apple, but the protocol has been reverse-engineered and is now used to stream playlists from non-Apple software (mainly on the Linux platform).

DAAP allows shared lists of songs within the same subnet to be automatically detected. When a song is shared, iTunes can stream the song but won't save it on the local hard drive, in order to prevent unauthorized copying. Songs in Protected AAC format can also be accessed but authentication is required. A maximum of five users may connect to a single user every 24 hours.

Originally with iTunes 4.0, users could freely access shared music anywhere over the Internet, in addition to one's own subnet, by specifying IP addresses of remote shared song libraries. Apple quickly removed this feature with version 4.0.1, claiming that users were violating the End User License Agreement.


On May 9, 2005, video support was introduced to iTunes with the release of iTunes 4.8. Users can drag and drop movie clips from the computer into the iTunes Library for cataloging and organization. They can be viewed in a small frame in the main iTunes display, in a separate window, or fullscreen. Before version 7 provided separate libraries for media types, videos were only distinguished from audio in the Library by a small icon resembling a TV screen and grouped with music in the library, organized by the same musical categories (such as "album" and "composer"). iTunes relies on Quicktime and is therefore incompatible with some common video formats, including WMV.

On October 12, 2005, Apple introduced iTunes 6.0, which added support for purchasing and viewing of video content from the iTunes Music Store. The iTunes Music Store initially offered a selection of several thousand Music Videos and five TV shows including most notably the ABC network's Lost and Desperate Housewives. Disney channels shows were also offered ( The Suite Life of Zack and Cody and That's So Raven) 24 hours after airing as well as episode packs from past seasons; since that time, the collection has expanded with content from numerous television networks. The iTunes Music Store also gives the ability to view Apple's large collection of movie trailers.

As of September 12, 2006, the newly-renamed iTunes Store offers over 200 television shows for download, including, most recently, additions from Discovery Channel, Comedy Central, MTV, and FOX. Additionally, a catalog of 75 feature-length movies from Disney-owned studios was introduced.

As of October 2006, movies and TV shows are only available to U.S. customers, with the only video content available to non-U.S. customers being music videos and Pixar's short films.

Video content available from the store used to be encoded as 540 kbit/s Protected MPEG-4 video ( H.264) with an approximately 128 kbit/s AAC audio track. Many videos and video podcasts currently require the latest version of Quicktime, Quicktime 7, which is incompatible with older versions of MacOS (only v10.3.9 and later are supported). Starting September 12, 2006, the resolution of video content sold on the iTunes Store was increased from 320x240 ( QVGA) to 640x480 ( VGA). The higher resolution video content is encoded as 1.5 Mbit/s Protected MPEG-4 video ( H.264) with an approximately 128 kbit/s AAC audio track.


iTunes supports visualizer plugins and device plugins. Visualizer plugins allow developers to create music-driven visual displays (iTunes includes a default visualizer, G-Force, licensed from SoundSpectrum). The visualizer plug-in software development kits for Mac and Windows can be downloaded for free from Apple. Device plugins allow support for additional music player devices, but Apple will only license the APIs to bona fide OEMs who sign a non-disclosure agreement.


Version 4.9 of iTunes, released on June 28, 2005, added built-in support for podcasting. It allows users to subscribe to podcasts in the iTunes Music Store or by entering the RSS feed URL. Once subscribed, the podcast will be downloaded automatically. Users can choose to update podcasts weekly, daily, hourly, or manually.

Users can select podcasts to listen to from the Podcast Directory, to which anyone can submit their podcast for placement. In this directory, Apple maintains four "official" podcasts: Podfinder (with Adam Curry), Street Official Real Talk (interviews with hip-hop artists), iTunes New Music Tuesday, and Apple Quarterly Earnings Call. The front page of the directory also displays high-profile podcasts from commercial broadcasters and independent podcasters. It also allows users to browse the podcasts by category or popularity.

The addition of podcasting functionality to a mainstream audio application like iTunes greatly helped bring podcasting to a much wider audience. Within days after iTunes 4.9 was released, podcasters were reporting that the number of downloads of their audio files had tripled, sometimes even quadrupled.

Video podcasting

Version 6 of iTunes introduced official support for video podcasting, although video and RSS support was already unofficially there in version 4.9. Users can subscribe to RSS feeds through the iTunes Music Store or by entering the feed URL. Video podcasts can contain downloadable video files (in MOV, MP4, M4V, or MPG format), but also streaming sources and even IPTV. Downloadable files can be synchronized to a video-capable iPod, and both downloadable files and streams can be shown in Apple's new Front Row Media Centre application.

Synchronizing iPod and other players

iTunes can automatically synchronize its music and video library with an iPod every time it is connected. (The OS X version of iTunes can also synchronize with a number of other digital music players; the Windows version will only support the iPod.) New songs and playlists are automatically copied to the iPod and songs that have been deleted from the library on the computer are also deleted from the iPod. Ratings awarded to songs on the iPod will sync back to the iTunes library and audiobooks will remember the current playback position.

Automatic synchronization can be turned off in favour of manually copying individual songs or complete playlists; however, iTunes supports only copying music to the iPod but not from it, which has inspired third party software for the latter purpose. It is also possible to copy from the iPod using ordinary Unix command line tools, or by simply enabling the "show hidden files and folders" option under "folder options", then copying music from the iPod drive to a local disk for backup.

When an iPod is connected that does not contain enough free space to sync the entire iTunes music library, a playlist will be created and given a name matching that of the connected iPod. This playlist can then be modified to the user's preference in song selection to fill the available space.

iTunes supports a number of other popular portable music players with some limitations, most notably the inability to play music purchased from the iTunes Music Store. Supported players include a number of NOMAD players from Creative Labs, some players from Rio Audio and Archos, and the Nakamichi SoundSpace 2 device. Other manufacturers may also offer integration by way of a device plugin. A number of third party programs have been created to help a user of iTunes to synchronize songs with any music player that can be mounted as an external drive.

Though iTunes is the only official method for synchronizing with the iPod, there are other programs available that allow the iPod to sync with other software players.

As of iTunes 7 purchased music can be copied from the iPod onto the computer. The computer must be authorized by that iTunes account. iTunes currently allows up to 5 computers to be authorized on one account. It does not allow you to transfer imported music files between computers. This may be necessary to back songs up, transfer songs to a new computer, or restore music after a disk failure using an iPod as the backup source. A number of shareware or freeware applications exist that complement iTunes.

iTunes Store

Version 4 of iTunes introduced the iTunes Music Store from which iTunes users can buy and download songs for use on a limited number of computers and an unlimited number of iPods. Songs purchased from the iTunes Store are copy protected with Apple's FairPlay digital rights management (DRM) system. As of February 22, 2006, over 1 billion songs have been downloaded since the service first launched on April 28, 2003.

Those who use an operating system other than Mac OS X or Microsoft Windows such as Linux cannot use music purchased from the iTunes Store, since a Linux version of iTunes is not available. This has resulted in the development of a number of alternative player software as well as published hacks or workarounds that allow customers of the iTunes Store to use the audio software or operating system software of their choice. The most notable of these hacks is PyMusique, which Apple has made several unsuccessful attempts at blocking. Software such as Hymn and SoundTaxi have also been developed that decrypt purchased music, to allow it to be played or shared on other programs. However, this software is illegal in some countries.

iPod owners in U.S. markets are taken to a one-time page within the iTunes Store when first connecting it to their computer. This page currently offers a free album sampler from Lava and Atlantic Records where either the whole album or individual tracks can be downloaded. An album sampler from Universal Records was previously available and may still be accessed via a special link on the web.

There are currently iTunes Stores available in the United States, United Kingdom, France, Germany, Austria, Belgium, Finland, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, Canada, Denmark, Norway, Sweden, Switzerland, Japan, and Australia.

In 2006, a controversy erupted about a French draft law aimed at reinforcing the protection of works of art against "piracy", or illegal copying; some clauses of the law could possibly be used to request Apple to provide information about its FairPlay system to manufacturers of competitor players.

The MiniStore feature was added in iTunes version 6.0.2. It adds a small window to the bottom of the main window, which can be turned on or off. When the user selects an item in their library, information about that particular item is sent to the iTunes Store, and the MiniStore shows related songs or videos. Initially, the MiniStore caused controversy because people feared it could be used as spyware. Apple clarified that the MiniStore didn't collect any information from users and later made it opt-in.

iTunes version 7 integrated "Cover Flow" technology, which allowed shoppers to view for album art through a 3D rollover interface. Originally created by for Mac OS X, the company was acquired by Apple Computer in 2006.

On September 12, 2006, the Store began offering movie and game downloads. To reflect the changes and to emphasize it as more than just an online music store, the iTunes Music Store was renamed as the iTunes Store. Apple announced on the same day that iTunes had become the first digital music store to be in the top 5 sellers of music in the U.S. It is currently in 5th place.


iTunes uses the Gracenote interactive audio CD database to provide track name listings for audio CDs. The service activates automatically when a CD is inserted into the computer while the iTunes application is open and an Internet connection is available. Track names for albums imported to iTunes while not connected to the Internet can be obtained later when connected, by a manual procedure. For any album loaded into iTunes for which there is not an existing Gracenote track listing, the user can choose to submit track name data to Gracenote.

Integration with other applications

On the Macintosh, iTunes is tightly integrated with Apple's iWork suite of applications and the rest of the applications in iLife. These applications can access the iTunes Library directly, allowing access to the playlists and songs stored within (including encrypted music purchased from the iTunes Music Store). Music files from iTunes can be embedded directly into Pages documents and can supply the score for iDVD, iMovie and Keynote productions. iTunes is also integrated with Front Row (Front Row reads its info from iTunes and iPhoto). In addition, any song exported from GarageBand, Apple's music-making program, is automatically added to the user's iTunes music library. iTunes' Artwork.saver is a screen saver included in Mac OS 10.4 that displays album artwork as a screen saver. iTunes.widget is a Dashboard Widget that controls iTunes. The development of Senuti for Mac OS X allows iTunes to be integrated so the iPod and iTunes can transfer songs to each other. Moreover, iTunes can be scripted, using AppleScript for Mac OS X or using the Apple-provided SDK for iTunes on Windows via Visual Basic, JavaScript, or C.

Recent version history

iTunes was developed from SoundJam MP, a popular commercial MP3 application distributed by the Macintosh software company Casady & Greene. Apple purchased the rights to the SoundJam MP software and hired the three programmers who created SoundJam. The first release of iTunes was very similar to SoundJam MP with the addition of CD burning and a makeover of the user interface as well as removal of SoundJam's recording ability and capacity of using skins. Apple has added a number of significant features in subsequent versions of iTunes.

  • 5.0 — September 7, 2005
    • Refined look (more compact)
    • 'LCD' display at top now displays artist and song together
    • Ability to group playlists in folders
    • Search now has Search Bar for refining search results. It duplicates the Spotlight bar in Mac OS X 10.4 Finder:
      • Search all music, audiobooks, podcasts, and videos, etc.
      • Search all artists, albums, and songs
    • Automatically sync calendars and contacts with Microsoft Outlook and Outlook Express (contacts only)
    • Smart shuffle (with adjustable 'randomness')
    • Support for the playback and creation of Variable Bitrate AAC files
    • Parental Controls to limit children's access to podcasts, the iTunes Music Store, and sharing features
    • Lyrics tab in track info box
    • Each song has the option to remember playback position and to skip it in shuffle mode
  • 5.0.1 — September 20, 2005
    • Bug fixes
    • Bonjour for Windows removed from installer bundle after DNS conflict problems
  • 6.0 — October 12, 2005
    • "Videos" added to Sources list
    • Supports purchase of video content through the iTunes Music Store
    • Can transfer video files to fifth-generation iPods
    • By purchasing music with 6.0 and further versions, iTunes Music Store account is upgraded, blocking the Hymn DRM removal utility
  • 6.0.1 — October 20, 2005
    • Bug fixes
  • 6.0.2 — January 10, 2006
    • Bug fixes
    • MiniStore in library (mini view of related products in itunes store)
    • Convert Home Movies to iPod compatible files in iTunes
    • AirTunes Enhancement to allow three separate audio streams
  • 6.0.3 — February 15, 2006
    • Bug fixes
    • Performance Improvements
  • 6.0.4 — March 1, 2006
    • Addresses stability and performance issues related to Front Row
  • - March 3, 2006
    • Fixes problems that some users have with playlists only in version 6.0.4
  • 6.0.5 - June 29, 2006
    • Adds Support for syncing Nike+iPod workout data to, to easily track progress, set training goals, and challenge others. New Nike Sport Music area on the iTunes Music Store to download workout mixes, Athlete Inspiration playlists, Nike podcasts.
  • 7.0 - September 12, 2006
    • Support for Movies downloaded from iTunes Store
      • Higher Video Resolutions (640x480)
    • Selectable User Interfaces and track listings
      • Cover Flow view for album art
      • Download Manager
      • Missing Album Art available for download from iTunes Store
      • Improved full screen video playback with onscreen controls
      • iPod Manager (iPod Updater is now built-in instead of being separate software)
    • Updated user interface
    • Improved Ratings and Parental Controls
    • Multiple Libraries and Library Backup commands
    • Gapless playback
    • Transfer of purchased content from iPod to computer
    • iPod Games
    • Improved Search
    • New data fields: "Album Artist", "Skip Count", and "Last Skipped"
  • 7.0.1 - September 27, 2006
    • Stability and performance improvements with Cover Flow, CD importing, iPod syncing, and more.
    • Resolved some compatibility issues with the Remote Desktop Protocol
    • Resolved compatibility with Windows Live Messenger and Computer Calls on PC's
  • 7.0.2 - October 31, 2006
    • Added support for 2nd generation iPod shuffle.
    • Fixed various stability and performance issues found in iTunes 7 and 7.0.1

Interface screenshots

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