Reel-to-reel tape recorders are audio recording devices that use magnetic tape to capture sound. The tape is wound around two reels, allowing for playback and recording. These machines were popular from the 1940s to the 1980s and are known for their high sound quality and durability. The technology behind reel-to-reel recorders involves a magnetic head that reads and writes audio signals onto the tape. Many professional musicians and studios, including those associated with The Beatles and Elvis Presley, used these devices for recording music, making them a significant part of audio history.