Proposed law changes will make it legal to copy music for personal use, but anyone recording a favourite television programme will be able to keep it for only a few days.
It is now illegal to copy music from a CD or tape to another device such as an iPod or an MP3 player.
But Parliament's commerce select committee has changed the Copyright (New Technologies) Bill to make it legal to "format shift" - or copy - music from a CD to other devices if it is for personal use.
The committee has not changed rules that render shelves of dusty videotapes illegal.
The current law allows home videotaping from TV, but only if programmes are kept for "no longer than is reasonably necessary for viewing ... at a more convenient time". That provision will remain.
And MPs on the committee have specified that copying DVDs or videotapes on to a device such as an iPod should not be permitted.
International treaty obligations did not allow the law change to extend to copying films, the committee said, and it did not consider such copying to be widespread.
Technology commentator David Farrar said it was ridiculous the law change would apply to sound recordings but not video. The same should apply to video sales, he said.
"If you pay for a DVD, why shouldn't you be able to copy it on to your video iPod so you can go to the gym and watch it?
"The big stupidity is that now you can do it, but you can keep it only for as long as it would reasonably take to watch it. It brings to mind the idea that the copyright police might check and say, 'This is three weeks old. You should have had time to view it by now'."
Technology commentator and Herald blogger Peter Griffin said refusing to allow video copying would not stop it happening. "You can't expect people to be ripping music and not ripping video."
But most commentators welcomed the news that copying music could soon be legal for the first time.
They were less happy with a proviso that gives music companies the right to opt out, by refusing permission for their music to be copied.
The change restricts copying to personal use, and it will still be illegal to make copies for friends or to copy borrowed or rented CDs.
Recording Industry Association chief executive Campbell Smith said most companies already turned a blind eye to personal copying, and association members had never taken legal action to prevent people taking copies for personal use.
"I think that's fair. You buy something for your own use and that's how it should be. We are in the business of trying to sell people music, not trying to prevent them doing what is reasonable."
Internet NZ spokesman Jordan Carter said the proposed law was still more restrictive than United States law, which had a long-standing principle of "fair use" under which it was automatically assumed people could copy for their own use music they had bought.
- additional reporting: Mike Houlahan