While i wholey agree with your last statement about asking for permission and that a deal can be made there are a few things you should consider:
copyright is not neccasarily automatic. it is only automatic in countries that adhere to rules from the berne convention (which Canada and the USA does)
another thing is that Copyright in a sound recording belongs to the maker of the recording instead of the author/creator. A maker is the person by whom the arrangements necessary for the first fixation of the sounds are undertaken. (Canadian law, not sure if USA is the same here)
the idea of fair use is very important as well. The copyright statute codifies the following four factors in weighing whether or not the use of a copyrighted work is a fair use:
this isimportant as most remixes generally repopularize the original, and do not negatively effect the market for the original work (there are exceptions)
regardless of if you breach copyright or not the point is does the copyright holder care? why would they sue to enforce it over a video you made, using aremix that someone else made. they dont. they arent going to do any more than remove the video. if you did not edit the video for the purposes of producing profit, then the company has no loss, and you cannot really be sued for damages. as well as how are they going to know you used it if google cant find it? if google with their vast resources cannot identify it, then there are very few that can. the only point i wanted to make was that if google cannot identify it, then you are safe using it in your edit, regardless of it if its is copyrighted or not. if you are indoubt you can always ask permission though.
anyway i dont want to argue, i guess i should have been clearer when i first replied to the thread. i will know for next time