Finding the right music

For our project we will find music non-copy right music from websites such as www.unsigned.com or www.youtube.com. We will look on these websites for idea's and non-copy right music which we would email the artist manger and write an email asking if we would be able to use there music for are video. We would need to tell them what school we are from, what year we are in ,names, what are idea is for the video.