How is music put onto CD’s and records etc?

Question: How is music put onto CD's and records etc?

Asked by hollylewisdavies to Laura, Lily, Mark, Paul, Sarah on 23 Jun 2010 in Categories: General.
- Mark Roberts answered on 21 Jun 2010:
  
  Music is just sound which is waves – so on a record their are grooves of varying height and this tells you the pitch of the sound you need to make at that time – so the height of the groove dictates the pitch of that sound so you can record the sound.
  
  CD’s use a laser to read the depth of a reflective surface but the idea is the same you etch different depths in a CD and the laser reads the depth and that tells you the pitch
  
  This is why CD’s and records don’t work when they get scratched.
- Lily Asquith answered on 21 Jun 2010:
  
  CDs have a spiral track on them with lots of little bumps and dips. They are too tiny to see or feel.
  When the laser in your CD player passes over the spiral track it senses the bumps and pits and converts them into binary data (ones and zeroes) and that is then converted into music following a set of rules.
- Sarah Bardsley answered on 21 Jun 2010:
  
  Wow – I’m not sure I know. If I gave you an answer I would just be copying wikipedia pages! I’m sure you can find that info yourself.
- Laura Maliszewski answered on 22 Jun 2010:
  
  For CDs I don’t know, it has something to do with refraction and lasers.
  
  You can learn more here: http://electronics.howstuffworks.com/cd.htm
- Paul Roche answered on 23 Jun 2010:
  
  With a CD, it is all to do with lasers – have a look here for how they work: http://www.howstuffworks.com/cd.htm
  
  With old-fashioned records, the vinyl (plastic) disc has actually grooves in it, which are detected by a pick-up – see:
  http://electronics.howstuffworks.com/record-player.htm

Question: How is music put onto CD's and records etc?

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