Audio mixing is used for sound recording, audio editing, and sound systems to balance the relative volume, frequency, and dynamic content of a number of sound sources. Typically, these sound sources are the different musical instruments in a band or vocalists, the sections of an orchestra, announcers and journalists, crowd noises, and so on.Another example is mixing two records together. Break beats are created by mixing between identical breaks. Often the end of one pre-recorded song is mixed into another so that the transition is seamless, which is done through beat-matching or beat-mixing, and possibly pitch control.At other times, audio mixing is done in studios as part of multitrack recording in order to produce digital or analog audio recordings, or as part of an album, film, or television program.An audio mixing console, or mixing desk, or mixing board, has numerous rotating controls (potentiometers) and sliding controls (faders which are also potentiometers) that are used to manipulate the volume, the addition of effects such as reverb, and frequency content (equalization) of audio signals. Audio mixing on a personal computer is also gaining momentum. More and more independent artists are starting to use their personal computers for digital recording and mixing their work. Audio editing on the computer is also easy and generally preferred.