A rightsholder is simply anyone that owns or administers parts of a song or a recording. This can be the music label, music publisher, song writers (s) or another entity.
Lickd has negotiated with artists and labels ahead of time, gets affordable rates, and makes it easy to find and license songs with no Content ID claim to worry about. Users can freely use great music and build a YouTube channel they can be proud of.
When YouTubers attempt to use music they don’t have permission to use, the most likely outcome is that rightsholders will take their ad revenue as compensation. In some cases, though, music may be restricted in general, which means the owner of the music can block your video entirely. It’s up to the owners of the song to decide what permission to give.