Sound mixing and recording is the process by which music is recorded and prepared for release. Pre-1925 sound recordings were made acoustically with sound waves driving the process. Sounds captured by collecting horns directed a stylus or similar device to cut grooves directly into a disc. The disc, usually made of wax, was used as a master to make copies. Recording studios were cramped and heavily curtained, making them uncomfortable for musicians. In 1925, recording became electric, and the first microphones were introduced. Styluses could cut a wider range of frequencies into grooves when driven by electric current, but until the 1940s, when magnetic tape became widely available, recordings could not be edited or mixed. The recording process was also limited by the time available on each disk. It also took an enormous amount of time to set up a studio, and each...