How Does a Cassette Tape Work?

Physical Properties of the Cassette Tape

Cassette Tape: 45 minutes per side (C90)
The hard plastic shell of the cassette tape protects the magnetic tape and two spools inside. As the magnetic tape is passed from one spool to another, the audio track plays uninterrupted. Professionally recorded cassette tapes often come professionally printed in hard plastic cases. Blank cassette tapes bear no marking; however, they usually come with sticky labels for personalization.

Old Boombox
In order to listen to a cassette tape, a user must have access to a stereo, boombox or tape recorder that is cassette tape compatible. Press the "stop" or "eject" button to open the cassette player. Place the cassette tape (magnetic tape-side down) into the cassette player.

Once the cassette tape is inserted into the machine, the cassette tape's spools fit over the spindles on the machine. When the user presses "Play," the playback head pushes against the tape. The friction causes an electromagnetic pulse, which results in sound.

A user can listen to the tape until it is finished, press fast-forward until all of the magnetic tape is collected on to one spool or manually flip the tape over to listen to the reverse side. An older boombox or stereo may have an "auto-reverse" button, which eliminates the need to manually flip the tape. Auto-reverse will switch the tape to its opposite side, enabling the user to listen to the reverse side of the tape.

Cassette tapes are used to record audio and data. The most common tape lengths are 30 minutes per side (C60), 45 minutes per side (C90) and 60 minutes per side (C120). When choosing a casette tape, a person should consider the intended usage of the tape. This will ensure the tape length corresponds with the amount of music or data to be recorded.

Cassette tapes were the first re-recordable alternative to vinyl records, which made them very popular in the 1980s. Additionally, the first home computers utilized cassette tapes for data storage, because cassette tapes were much cheaper than floppy disks in the late 1970s and early 1980s.