Copyright holder - can't find who?

As you are tasked with evidencing contacting the rights holder and asking for permission for your non-commercial use of their track, you obviously need to know which company to contact. Looking at physical media (the CD) is an obvious starting point - you can generally find sleeves on a number of websites which specialise in just this. You can also try the band's official site, and look up Wikis etc.
If still struggling, yet another method can be your YouTube account ...
As I've previously blogged, you should look out for (hyperlinked) messages under your uploads, such as 'Video blocked in some countries'. Just click on these to then click 'acknowledge', keeping your account in good standing. You should find specific reference there of which company claims copyright of the recording, such as in this example from an upload of a student music video for a Storm Queen track: