Quote: "I heard from a sound lecturer that if the song is altered by more than 10 percent then you can claim it as original"
Its actually
over 10 percent of a music piece to put you on shaky ground,only
less than 10 percent similar is not accepted as copying, so your song would need to be 90 percent altered. Using actual recordings ie. sampling is not acceptable without permission in this case as the recording itself is covered by mechanical copyright
Parody is recognized as a form of fair use, even if the parody is designed to sound like the original. In the U.S., the parody exemption comes from the First Amendment guarantee of Freedom of Speech.
I would reckon the same applies in EU where you have always had comedy shows parody songs with impunity.
Quote: "I play known songs on my keyboard but alter them a bit. I wonder what the copyright says about that? When you watch the X factor everyone is making a known song in their own style, nobody seems to worry about copyright. Same with Karaoke."
Such shows as the Xfactor or even karaoke have their own licenses, you might even find that karaoke is covered by the venues license, bars and clubs pay a license fee for public performance.
Intent is a large part of music copyright infringement, if you record and release these songs commercially your on shaky ground, if you only intend to perform them live your fine. If you expect to sell less than 3000 units or so you could look into licensing each of them, it only costs around 15 bucks per song for this kind of license.
As for Men at Work what they had copied was the melody of the flute interlude on the recording.
I remember David Bowie and the Sweet controversy for ripping the riff from Jean Genie which I believe Bowie took in good humour, if he had wanted to sue he would most likely have won hands down, thing is, both songs sat in the top ten with The Sweet at number one.
Awesome! Its one of those threads.