An album is a collection of audio recordings issued as a single item on CD, record, audio tape or another medium. Albums of recorded music were developed in the early 20th century, first as books of individual 78rpm records, then from 1948 as vinyl LP records played at 33 1⁄3 rpm. Vinyl LPs are still issued, though in the 21st-century album sales have mostly focused on compact disc (CD) and MP3 formats. However, vinyl sales have been on the rise in recent years. The audio cassette was a format used alongside vinyl from the 1970s into the first decade of the 2000s.
An album may be recorded in a recording studio (fixed or mobile), in a concert venue, at home, in the field, or a mix of places. The time frame for completely recording an album varies between a few hours and several years. This process usually requires several takes with different parts recorded separately, and then brought or "mixed" together. Recordings that are done in one take without overdubbing are termed "live", even when done in a studio. Studios are built to absorb sound, eliminating reverberation, so as to assist in mixing different takes; other locations, such as concert venues and some "live rooms", allow for reverberation, which creates a "live" sound.
