There might be some music in the public domain that can be used. But public domain music is basically stuff thats so old the copyright has expired, and/or, nobody ever claimed copyright. But even public domain material can be legally murky.
You have to be very careful with copyright material. I use buyout music, another option, when I edit wedding videos. "Buyout music" is music that the artist not only sells you but also sells you the right to use commercially, normally with some kind of limits written in the contract that comes with it. Try explaining to a bride why you cant play "The Beatles" as she's walking down the isle of her wedding? Another reason I got out of the bizz.
It even goes deeper then that with copyright laws on Intellectual property. If you copy a CD or DVD for backup, "yes the discs do go bad", your actually breaking the law. And a Federal one at that. But generally the standard used for prosecution is if an agent is using it for some kind of personal benefit or monetary gain. For instance if you use copyrighted material on you tube to promote your business you might have a problem. If you just use it for your cartoon airplane video, for recreational purposes, then probably nobody is going to bother you. However you are still breaking the law. If you copy Hollywood movies by the thousands, and sell them on the side, you might have a very, very big legal problem. The entertainment industry does not strike me as a conglomerate you want to make enemies with casually.
I'm sure nobody knows all of this better then our favorite cartoon airplane maker. I have a stereo by my flight desk. So when I'm in the mood I put on some music to accompany my getting shot up all night long.
