i have just made a film and used some music samples from this site, credit to the auther and freesound have been given. so i think that is ok. some one i know has seen the film and wants to use it to promote his business. i have tried to contact the author but have had no reply. reading the forum i gather that this is not possible even if no cash changes hands. am i correct
Yes, if the music is used commercially, then the Right Thing to do is to continue to try to find the author. Otherwise have the potential client hire you to produce music that is similar to what was heard. You can then sub-contract musicians or find library music that is close.