like for a youtube video how much of a song can i use without infringing anyone's copyright?

All Answers To Questions

Fair use is codified at Section 107 of the Copyright Act, which gives a non-exclusive set of four factors courts will consider in deciding whether a use is fair or not. These factors are 1. the purpose and character of the use, 2. the nature of the copyrighted work, 3. the amount and substantiality of the portion used, and 4. the effect of the use on the potential market for or value of the copyrighted work. There are no legal rules permitting the use of a specific number of words, a certain number of musical notes, or percentage of a work. Whether a particular use qualifies as fair use depends on all the factors listed above and potentially others. As an example, in Bridgeport Music, Inc. et. al. vs. Dimension Films et. al., the Sixth Circuit found that the use of two seconds from a sound recording was NOT fair use. I highly recommend you read this case to get more background on the concept of fair use. http://www.chillingeffects.org/fairuse/ http://www.copyright.gov/help/faq/faq-fairuse.html http://fsnews.findlaw.com/cases/6th/04a0297p.html

no hard and fast rules, depends on the circumstances. could be all of it, could be none of it if such are the circumstances.