how do cassette tapes generate sound?

Question

It's weird for me to look at the strech of tape and think that somehow it creates all the complex sounds in music. Is it the tape it self or is there some code on the tape that gets transferred to the tape player and the sound is produced electronically?

Answer 1

Very tiny magnetic dust is on the tape. The magnetic dust is moved around as tape rolls according to the sound pushed onto it with a magnet. Playing it back, it reads the differences in the magnetic dust (causing different magnetic strength) which is amplified creating sounds...

http://electronics.howstuffworks.com/cassette2.htm

Answer 2

Cassettes are analogue technology, and use induction to create sound. When you pass a magnet past a coil of wire, it generates a small electric current.
The tape is coated with magnetic material. When the tape passes over the tape head, it causes a current to run through the coils inside the head. The varying magnetism on the tape causes a varying current in the tape head, which is amplified and played on your speakers. This is the music you hear.

Answer 3

The tape is coated with a special form of iron oxide. As it passes the recording head of a tape recorder, the audio signal, in the form of electromagnetic pulses, magnetizes the tape in a pattern which matches the audio signal (i.e., the music). When it passes by a playback head of a tape player, the magnetized iron oxide particles induce a small electric current in the head, corresponding to what was recorded, and the tape player sends this signal to an amplifier.