But would that apply to a video of a singer performing a copyright song in a sing around session?

What about recordings of school choirs performing or people giving music lessons or showing their growing prowess on various instruments?

This is such a contentious topic. Joe's analogy is interesting, but it may be a little shooting in the foot for original artists because more exposure may mean more purchases of CDs and attendance to concerts. It could be free publicity. Youtube videos are not a commercial product for the poster are they?

I have been approached to provide background audio to video photo compilation project. I will not be paid and neither does the videographer plan to profit by it. A hobby to do something with photos taken while he was a truck driver in the US. Does this mean we need to get permission for me to sing and play music still under copyright and for him to post the finished video on youtube?