A&R (Artist and Repertoire) - Record label employees who are in charge of finding and signing new bands.
 
AAC (Advanced Audio Coding) - Also called MPEG-2 AAC or MPEG-2 NBC, this audio codec is the logical continuation of the MP3 codec created by Fraunhofer-Gesellschaft. Due to advances in the technology, AAC files encoded at a 96 kbps bit rate sound slightly better than MP3s encoded at 128 kbps. For more information, see here.
 
ADC (analog-to-digital converter) - This type of converter changes an analog electrical signal into a digital signal made of 1s and 0s. When you make a voice or line-in recording with your MP3 player, you are using the device's ADC.
 
ADPCM (Adaptive Differential Pulse Code Modulation) - This method of encoding sound data files takes up less storage space than the regular PCM format used by WAV and AIFF files--and CD audio for that matter. ADPCM comes in more than one flavor: IMA's ADPCM, for example, is used on the Sony MiniDisc to cram more data onto a smaller platter; Microsoft's ADPCM is used as part of Windows 95's canon of audio codecs. Many MP3 players use ADPCM for their voice-recording feature.
 
AIFF - An uncompressed Macintosh audio file. WAV files occupy an incredible amount of disk space, thus the need for compressed formats, such as MP3s.
 
ASCAP - An organization that collects royalties for its members (artists, bands, and music publishers) when their music gets played on the radio, the Web, or in public. Find out more here.
 
ATRAC - The audio compression algorithm used by MiniDisc players. It involves dropping all frequencies below and above the human hearing range (20Hz to 20KHz).
 
ATRAC3 - The audio codec used by MDLP MiniDisc players and Sony MP3 players.
 
audio compression - audio compression works by setting a limit for how loud sound can get while raising low parts of a song to a certain extent, depending on the level of compression. Basically, the lowest and highest volume levels of a song get closer together.
 
audio player - A program that turns the 1s and 0s in an audio file into an audio signal.
 
bandwidth - The size of the "pipe" that brings information to and from computers over the Internet. Low bandwidth includes rates of 28 kbps and 56 kbps, while high-bandwidth (broadband) connections deliver more information at a faster pace, making full-screen video, for example, possible.
 
bit rate - in essence, a measure of how many bits describes each sound in an audio file. A low bit rate means lower quality and a smaller file size, while a high bit rate means better quality and larger files. The standard bit rate is 128 kbps.
 
BMI - An organization that collects royalties for its members (artists, bands, and music publishers) when their music gets played on the radio, the Web, or in public. Find out more here.
 
buffer - An area of memory (usually on your hard drive) that is shared by two enabling processes, which run at different speeds to sync up with each other. For example, a buffer designed for streaming audio helps a patchy data stream from a server sound consistent when played by your computer's audio software.
 
buffering - The process by which streaming audio and video saves data in advance of playing it. Programs such as RealPlayer or Windows Media Player will download a part of the video or audio stream before starting to play, then continue the downloading as the stream plays. If the playing catches up to the end of the buffer, the stream will pause while further buffering occurs.
 
CD burning - The process of using a CD-R/RW drive and burning software to put data or audio onto a CD.
 
CD-R disc - A read-only CD that cannot be rewritten. A normal CD player can read a CD-R that the burning software specified as an Audio CD when the disc was created.
 
CD-RW disc - A CD that can be erased and rewritten. It can't be read by normal CD players, but it works great for burning compressed music for computer playback.
 
CD-R/RW drive - A drive capable of writing to CD-R and CD-RW discs.
 
CDA - The format of audio on a standard RedBook CD; can be extracted to your hard drive by a ripper into WAV (Windows) or AIFF (Macintosh) files.
 
CDDB - A centralized database on the Web that can recognize most CDs and send track listings to your audio player so that you don't have to type in all the information yourself.
 
CD text - A method for including text on normal, otherwise RedBook-standard CDs, denoting the title of the CD, the name of the artist, the track information, and more.
 
codec - A codec is an algorithm for compressing and decompressing audio and video files without losing a significant amount of information. Once a file has been compressed by a codec like MP3 or RealAudio, it is smaller and easier to transmit across the Web, and still sounds fairly true to the original.
 
compulsory license - This type of licensing means that whoever wants to broadcast a song owned by someone else can do so as long as they pay the rate set by the relevant industry organization. The lack of compulsory licensing for music downloads has stalled the efforts of online music distributors to go legit.
 
CRC (Cyclical Redundancy Checking) - A 16-bit number that sits in every frame of some MP3 files and is used to check for errors in streaming audio and MP3 playback. CRC degrades sound quality slightly because it takes up room in the file that would otherwise be used for the audio data itself. Most MP3s have no CRCs.
 
DAC (digital-to-analog converter) - A circuit that turns the digital 1s and 0s representing a sound to an analog waveform (which, in turn, is usually amplified and turned into audible sound).
 
DAT (Digital Audio Tape) - A small cassette that records and plays back audio digitally, at CD quality and better.
 
download - To copy a file (for example, a program or MP3 file) from a server to your machine, a.k.a. the client.
 
DRM (Digital Rights Management) - A secure technology which enables the copyright owner of a piece of intellectual property (such as a music, video, or text file) to specify what a user can do with it. Typically, this is used to offer downloads without having to worry that the user is freely distributing the file over the Web without any compensation to the copyright holder.
 
DSP (Digital Signal Processing) - The (usually real-time) processing of an audio signal in such a way that it sounds different from the original. Examples include: bass boost; 3D simulation; and Rock, Jazz, and Classical presets.
 
encoder - Software that turns uncompressed WAV (Windows) or AIFF files into compressed files, using a CODEC such as MP3 or RealAudio.
 
EQ (equalization) - A filter for audio that increases or decreases volume at certain frequencies, so that treble, bass, or midrange sounds can be amplified or quieted. Most audio devices and playback software contain some EQ options.
 
firmware - The operating system and software installed on a portable device. Some MP3 players have upgradable firmware, meaning that their operating systems can be updated to support future audio codecs or make small performance tweaks such as improved power efficiency.
 
FLAC (Free Lossless Audio Codec) - This open-source codec compresses audio by about 50 percent, but the good news is that it does not lose a single bit during the process. Like other lossless codecs, FLAC works in mysterious ways, by finding parts of an audio file with a bunch of 1s or 0s in a row and describing 11111 as five 1s. The details are much more complicated, but that's the basic idea. FLAC is a favorite of audiophiles because it sounds exactly as good as the original CD.
 
flash memory - Small, flat, solid-state type of memory used in MP3 players, digital cameras, and PDAs. It comprises CompactFlash, SmartMedia, and Memory Stick memory; on per-megabyte basis, it is a very expensive form of storage.
 
FTP - An Internet protocol used to copy files between computers; usually a client and an archive site filled with MP3 files or whatever else the server administrator has seen fit to upload. You can download shareware or freeware apps (for PC or Macintosh) that deal with the whole process for you, so that you don't have to communicate with the FTP server in its own language (Unix).
 
ID3 - The tag embedded in MP3s that tells your MP3 file what song, artists, and album it comes from. These tags can be edited.
 
IRC (Internet Relay Chat) - An Internet chat setup that uses client/server software and permits people to exchange files such as MP3s with each other while chatting. Download an IRC client here.
 
ISO 9660 - A standard format, invented by High Sierra in 1988, for burning CD-Rs and CD-RWs. In the ISO 9660 format, directories and filenames get chopped to eight letters..
 
Janus - Also known as Windows Media DRM 10.0, the Microsoft technology that allows an expiration date to be attached to the licenses for Windows media (WMA and WMV) files. Janus-enabled services can effectively rent out content to compatible portable devices such as MP3 players and PVPs since the files will time out after a set period.
 
Joliet - A standard format for burning CD-Rs and CD-RWs, created as an extension to ISO 9660 by Microsoft as part of Windows 95. In the Joliet format, long filenames are preserved.
 
jukebox - A multipurpose audio program that usually incorporates an audio player, a ripper, an encoder, and a file organizer.
 
LAME - Originally an acronym for LAME ain't an MP3 encoder, LAME has evolved into a high-quality, high-speed, and free MP3 encoding engine. Open-source developers began LAME as an educational project to improve psychoacoustics, noise shaping, and encoding efficiency. Today, the engine (found in many forms, from uncompiled source code to software applications) has a reputation of delivering the best-sounding MP3s.
 
line-in (line-level input) - An audio input that records from line-level sources such as CD players, home stereos, sound cards, tape decks, headphone outputs, or powered microphones.
 
line out - This output sends an audio signal to its intended destination. You might use a line out to send an audio signal from a portable device to a receiver or from a receiver to a recording device or from a portable device to a pair of powered speakers.
 
Liquid Audio - A secure, proprietary compressed audio format that lets artists offer downloads at a cost. Download the client for Mac or PC.
 
M3U - When you create a playlist in audio playback software such as Winamp, the playlist file contains the extension M3U. Clicking an M3U file will bring up all of the songs in the playlist in your default audio player.
 
MDLP
A method for doubling or quadrupling the amoung of audio that a MiniDisc can hold, using ATRAC3 compression.
 
MIDI - MIDI (Musical Instrument Digital Interface) is a protocol that allows electronic musical instruments to talk to each other and to computers. Because MIDI files contain only a series of commands (such as note on, note off), they are very small and efficient. On the other hand, they have no sound of their own, and must be used in conjunction with a wavetable, a synthesizer, or a drum machine.
 
mirror - An alternate location for a file on the Internet, initiated to avoid placing undue strain on the primary server where the file resides.
 
mono - One channel of audio. When you listen to something in mono, the exact same sound comes out of the left and right speakers or headphones. Since mono tracks contain half the information of an equivalent stereo file, they are half the size.
 
MP2 - A compressed MPEG1 sound file used before MP3 that is larger than the now favored MP3 format.
 
MP3 - A sound file that has been compressed through MP3 encoding, making the files smaller and easier to send across the Internet.
 
MPEG (Moving Pictures Experts Group) - MPEG is a standard for compressing sound and movie files into an attractive format for downloading--or even streaming--across the Internet. The MPEG-1 standard streams video and sound data at 150 kilobytes per second--the same rate as a single-speed CD-ROM drive--which it manages by taking key frames of video and filling only the areas that change between the frames.
 
normalize - A process that adjusts the volume of a sound recording so that it plays back at a consistent volume.
 
OELD - short for organic electroluminescence display. Also written as OEL screen or OEL display. Same as OLED.
 
Ogg Vorbis - This is an open-source codec, meaning (among other things) that no one has to pay licensing fees when it's used, unlike codecs such as MP3, WMA, or AAC. Many focus groups claim that music files compressed by the Ogg Vorbis codec (extension: OGG) sound better than those created with commercial codecs.
 
OLED - Short for organic light-emitting diode. A display device that operates by sandwiching carbon-based films between two charged electrodes. OLED displays are unlike LCDs in that they don't require backlighting; instead, they emit light themselves. OLED displays offer many advantages over LCDs, including less power consumption and brighter output, and are increasingly showing up in MP3 players and other portable devices.
 
open source - Software (usually developed by a group of volunteers) with no restrictions on other people using it for free, rewriting parts of the code, or redistributing it in its original form.
 
playlist - A sequential list of songs that can include CD audio, MP3s, WMAs, or any other kind of audio file. Playlists can be randomized to create a mix and saved to hard drives and CD-Rs.
 
psychoacoustics - the science of how ears perceive the loudness, pitch, and quality of sound, which is used to develop codecs that compress sound data and make our ears think that nothing is missing, among other things.
 
quantize - Even musicians with an amazing sense of rhythm don't always get the intervals between notes or beats exactly right. Quantizing MIDI music aligns the music exactly to the tempo and time signature that you specify.
 
RedBook CD - A CD filled with uncompressed audio in the CDA format used by CD burning software in the audio mode; also, the type of CD you buy in stores.
 
RIAA - An organization representing many music labels, from small indies to the majors. Find out more on its Web site.
 
ripper - Software that digitally yanks tunes from your CDs and turns them into files on your computer (WAV files in Windows, AIFF files on a Mac).
 
sampling rate - The precision with which a digital file describes the analog sound it represents. Basically, a lower rate produces files that sound worse and take up less drive space than those with a higher rate. CDs have a sampling rate of 44.1 kHz, and DAT machines have a sampling rate of 48 kHz. MiniDisc player/recorders with a built-in sampling rate converter can handle both rates.
 
SDMI - A consortium of music industry companies that is trying to come up with a way to make online music secure and salable. Find out more on its Web site.
 
secure audio file - A downloadable music file that must be paid for in order to be heard and/or cannot be duplicated without some loss of audio quality.
 
sideload - When instead of downloading something from a server, you send it over to the space in your account on a third-party storage site.
 
signal-to-noise ratio - A measure of the strength of the audio signal in comparison to that of the background noise. Essentially, a low signal-to-noise ratio means that the device or file has lots of hiss and static, while a high rating means clear-sounding audio.
 
skin - You can change all kinds of graphical elements of skin-enabled programs such as Winamp or Sonique by creating skins.
 
sound card - A piece of circuitry you can add to your computer that allows it to play and record sound. Sound cards have outputs on the back in a variety of formats that enables sound to travel to headphones, speakers, stereos, MiniDisc players, and so on. Typically, sound cards accept and emit analog signals, but some specialized sound cards handle digital input and output.
 
S/PDIF (Sony/Philips Digital Interface) - A standard format used for transferring data between two digital audio devices over (more commonly) a standard RCA cable or (less commonly) an optical cable.
 
splitter - A cable or adapter with one input or output on one end and two on the other.
 
spoof - To make a computer pretend to be someone else's computer by identifying itself using the same IP address as the victim's machine. In this way, it can be possible to pretend to be that person in many Internet protocols (posting to Usenet, sending ICQ messages, and so on).
 
SRS - A type of DSP that can add a three-dimensional sound effect to your music, as well as intensify the bass, if you so desire. With most MP3 players that have SRS capabilities, you can configure the feature to sound right to your ears.
 
standard bit rate (SBR) - The standard type of compression wherein an entire audio file is encoded at the same bit rate, as opposed to variable bit rate encoding.
 
stereo - Two channels of audio. When you listen to something in stereo, different sounds come out of the left and right speakers or headphones. Since stereo tracks contain twice the information of an equivalent mono file, they are twice the size.
 
streaming - The transmission of audio across the Internet from a server to an audio player client.
 
TOSLINK - A type of digital connection that uses optical signals to send a signal flawlessly, without losing any information. It's used for connecting MiniDisc players to stereos and certain sound cards.
 
transcode - To encode music from one codec into another codec--for example, from RealAudio to MP3.
 
variable bit rate (VBR) - A type of compression wherein certain audio sections are encoded at different bit rates so that complex sounds are encoded at a higher rate while simple sounds are encoded at a lower rate, as opposed to standard bit rate encoding. This means you get the best sound possible for a certain amount of disk space, but certain players occasionally have problems decoding VBR audio files.
 
visualization - A feature or plug-in in a software audio player that renders shapes and colors in sync with the music.
 
VQF - A compression algorithm developed by Yamaha that is similar to MP3 yet occupies less hard drive space. Find out more at VQF.com
 
VST plug-in - VST plug-ins are a standardized type of effects plug-in, used in conjunction with digital multitracking software. The major benefit of using VST plug-ins is that they can be applied to audio in real time, the way hardware audio effects can be.
 
watermark - Aunique inaudible code, which is inserted into an audio file in order to identify the first person who legally purchased the file. If you buy a watermarked MP3 and then distribute it over the Internet, the RIAA will be able to tell that you are the person who originally broke copyright law and distributed the file. Watermarks have yet to be deployed by the SDMI.
 
WAV - An uncompressed Windows audio file. WAV files occupy an incredible amount of disk space, thus the need for compressed formats, such as MP3.
 
WMA - The Windows Media Player format, which (according to independent testing) sounds as good as MP3 at half the bit rate (and therefore half the file size).