itunes

iTunes is an audio player, written by Apple Computer, for playing and organizing digital music files, and purchasing digital music files protected or encumbered by FairPlay digital rights management. The iTunes Music Store (also sometimes referred to simply as "iTunes") is the component of iTunes through which users can purchase digital music files from within iTunes. The player has gained and maintained a reputation as being easy to use, while still allowing users to precisely organize their music (e.g., smart playlist). iTunes is used to fill Apple's popular MP3 music player iPod with songs. The program is freely downloadable and is also supplied with Mac OS X as well as Apple's iLife home-application suite. iTunes is compatible with computers running Mac OS X, Windows 2000, or Windows XP operating systems (not Windows 98 and the like). Earlier versions of iTunes also run on Mac OS 9. Compatability with other operating systems such as Linux is not currently available.

Features

Users are able to organize their music into playlists, edit file information, record compact discs, copy files to a digital audio player, purchase music on the Internet through its built-in music store, run a visualizer to display graphical effects in time to the music as well as encode music into a number of different audio formats. 'Smart playlists' are playlists that are automatically updated (like a database query) based on a customized list of selection criteria.

Music library

iTunes stores metadata about the audio files in two files. The first is a binary file called iTunes 4 Music Library that uses its own music library format, independent of the audio format's tag capabilities (for example the ID3 tag). The second file, called iTunes Music Library.xml, uses XML format, allowing developers to easily write applications that can access the information (e.g. Apple's own iDVD, iMovie, and iPhoto or Freshly Squeezed Software's Rock Star).

File format support

iTunes can currently encode to MP3, AIFF, WAV, MPEG-4 AAC, and Apple Lossless, and can play anything QuickTime can play (even video formats, as long as they have audio), including Protected AAC files from the iTunes Music Store, plus Audible.com audio books. It can be extended to play other formats such as the free Ogg Vorbis audio format through the addition of QuickTime components. However, critics suggest that Apple have neglected their MP3 encoder in favor of the AAC encoder. In a January 2004 double-blind public listening test of six MP3 encoders encoding at 128kbps, conducted by Roberto Amorim, the iTunes MP3 encoder came last. http://www.rjamorim.com/test/mp3-128/results.html The Windows version of iTunes can automatically convert unprotected WMA files to other audio formats, but it does not support direct playback or encoding of WMA format.

Music sharing

iTunes Library songs can be shared over a local network using Rendezvous - Apple's implementation of the Zeroconf (zero configuration required) open network standard - which 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 a copy on the local hard drive, in order to prevent piracy. Songs in Protected AAC format can also be accessed but authentication is required. Originally with iTunes 4.0, users could access shared music anywhere over the internet, in addition to one's own subnet, by specifying IP addresses of remote shared song libraries. This feature was soon removed by Apple with version 4.0.1, claiming that users were violating the EULA. Music sharing uses the Digital Audio Access Protocol (DAAP), created by Apple for this purpose. http://daap.sourceforge.net/ Just days after the Windows version of iTunes was released, Bill Zeller, a 20-year-old Trinity College student, wrote myTunes, a program which allows Windows users to circumvent the iTunes restriction and download music from an iTunes shared playlist over a network. The program quickly became popular and is now widely used. There also exists a similar open source Java client, called ourTunes.

Plugins

iTunes supports visualizer plugins and device plugins. Visualizer plugins allow developers to create music-driven visual displays (iTunes includes a default visualizer). The visualizer plugin 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 an NDA.

Synchronizing iPod and other players

iTunes can automatically synchronize its music library with an iPod or other supported digital music player every time it is connected. New songs and playlists are automatically copied to the iPod and songs which 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 favor of manually copying individual songs or complete playlists; however, iTunes supports only copying music to the iPod and not from it, which has inspired third party tools for that purpose. It is also possible to copy from the iPod using ordinary Unix command line tools. 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. iPod owners in US markets are taken to a one-time page within the iTunes Music 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. 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 the Nakamichi SoundSpace 2 device. Other manufacturers may also offer integration by way of a device plugin.

iTunes Music Store

Version 4 of iTunes introduced the iTunes Music Store from which iTunes users can legally buy and download songs for use on a limited number of computers and iPods. Songs purchased from the iTunes Music Store are copy protected with Apple's FairPlay digital rights management (DRM) scheme. To date, over 300 million songs have been downloaded since the service first launched in April 2003.

iTunes 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. Apple has added a number of significant features in subsequent versions. Mac OS 9

1.0 - January 9 2001

Original release.

1.1 - February 21 2001

Support for external burners.
Improved visual effects generator.
More supported burners.

Mac OS 9 & Mac OS X

2.0 - November 2 2001

iPod support.
Equalizer.
MP3 CD burning.
Crossfader.
Sound enhancer.
Burns CDs 2x faster than before.
Unicode metadata and ID3 tag support.

2.0.2 - November 16 2001

Language support for French and German.

2.0.3 - December 13 2001

Only checked songs are synchronized with iPod.
Rio One MP3 player support.

2.0.4 - March 20 2002

Expanded AppleScript support.
Improved stability and performance.

Mac OS X

3.0 - July 17 2002

Smart playlists.
Audible.com audio book support.
Sound check.
Ratings.
Play counts.
Join tracks.
Playlist importing and exporting.

3.0.1 - September 18 2002

Performance improvements.
Better support for Mac OS X 10.2.

4.0 - April 28 2003

Music Store support.
Music sharing.
AAC audio codec.
Album artwork.
DVD burning support.
Improved searching.
Beats per minute field.

4.0.1 - May 27 2003

Music sharing only in subnet.
Performance improvements.

Mac OS X & Windows

4.1 - October 16 2003

Voice notes and On-The-Go playlists synchronization with iPod.
Support for large library to be burned on multiple CDs.
Music Store link drag & dropping.
Music Store now features Audiobooks.
Music Store has more advanced Power Search.
Music Store supports allowance.
Music Store supports gift certificates.

4.2 - December 18 2003

AOL account support in Music Store.
Performance improvements.

4.5 - April 28 2004

iMix.
Party Shuffle.
CD insert printing.
Music Store Quick Links.
Automatic WMA to AAC conversion (Windows only).
Apple Lossless audio codec.

4.6 - June 9 2004

AirTunes support.
Minor improvements.

4.7 - October 27 2004

Support for copying photos to an iPod photo.
Ability to show duplicate songs in your library.
Performance improvements.
iPod preferences now part of the Preferences window.
Ability to search iMixes by name on the iTunes Music Store.
Taskbar iTunes toolbar, minimize to tray (Windows-only)

4.7.1 - January 11 2005

Support for iPod shuffle and "Autofill" functionality.
Disallows play and transfer of Music Store-purchased tracks that have had the DRM-protection stripped by third-party applications.
Only allows 5 connections per day to libraries shared over a network