In Germany there is a strong copyright for music and pictures. So, please, use one of these platforms if you want to have free music for your video.
www.jamendo.com
www.soundcloud.com
www.bandcamp.com (only partly free)
www.restorm.com
Most of these webpages offer the possibility to search for songs after certain aspects. But even if you are not restricted like we in Germany, this might be interesting for you, because there are thousands of songs.