Audio recording has been with us for more than a hundred years. The phonograph was invented by Thomas Edison in 1877. It recorded sound by producing grooves on a soft cylinder which could be played back by running a needle through the grooves and amplifying the sound.

The next major development in audio recording was magnetic recording. Tape recorders were developed in Germany and have been in common use from the early 1930s up until recently. They are still being used, but are increasingly being supplanted by digital recorders.

Magnetic tape recorders have been the essential tools in the development of the recorded music industry. With the introduction of multitrack tape recorders in the 1950s, came the ability to produce new multilayered sounds. Audio recording using four track tape recorders was the standard during the 1960s. When the first four tracks were completed, they were "bounced down� to the first track of a second tape recorder. This allowed the creation of complex musical arrangements.

All the major recording artists of the 1960s used four track tape recorders for their recordings. The limitation to this method of audio recording was the buildup of noise as the tracks were bounced from one machine to another. This was overcome with the introduction of wider magnetic tape that could record 24 tracks or more. This meant that each instrument could be recorded on its own track without any appreciable buildup of noise.

Digital audio recording was introduced in the 1990s and has now become the norm. There are several formats for recording digital audio including Digital Audio Tape (DAT) and hard disk recording. Digital playback devices include MP3 players, CDs and MiniDisks. Digital audio recording and playback offers a clean, noise free and long lasting medium.

Despite the technological advances, some audio recording techniques have remained basically the same since the 1920s. Microphones are still used to capture the sound produced by acoustic instruments and voices. Many instruments today, however, are synthesized, and recorded directly onto the recording medium without the use of microphones.

Computers can be used to automate some of the processes in audio recording. Computers can emulate all the functions of a recording console and can be programmed to fade in and out and add effects like reverb. Computers open up new possibilities in audio recording which for the most part are unutilized in popular music.