Problems with music

The biggest problem i believe that we have faced so far would be choosing the right type of music to use in our intro film, me and my partner choose to have music at the start of our film and then dim it out after a specific amount of time. However, this proved to be a big problem as we coulnd't find any music to put into our film that was copyright free, we spent many hours searching different websites to try and find music which we were able to use in our film, we did find a piece that fit perectly into our film but it was copyright and we were unable to use it.