Sonick, with all due respect, your question is a thorny one; crossing jurisdictional boundaries by taking music online subjects you to a multitude of laws on the matter. Honestly, seek out legal advice. For general informational purposes only (and in no way rendering legal or any advice), many online are operating under the mistaken belief that there is a non-commercial use exception which allows them to upload/download works, but which belief is untrue: basically, there's no such thing in the US as non-commercial use rights. Also, in the case of a sound recording, different copyrights attach, namely, one in the musical composition itself (notes and lyrics), and one in the record (its artistic rendering as captured in the recording of that song). In other words, when using a recording, there are two separate but equally important copyrights involved. Simply put, using a copyrighted work without its owner's express permission-or a license-is copyright infringement unless found to be a Fair Use under the US Const., but Fair Use generally speaking doesn't recognize commercial use (i.e., wherever doubt, get a license). Canada's "fair use" doctrine (known as "fair dealing") is really thin by comparison to the US doctrine, there being fewer albeit much clearer exceptions. Also, unlike the US, Canada (and the EU) recognize what's known as droit moral (Moral Rights), and which are in addition to the already noted copyrights in the work. Basically, moral rights belong to the owner of the work, protecting the integrity of the work as the owner sees fit (i.e., another bundle of thorny issues). Copyright durations vary from nation to nation, but last a very long time (note: in many places, it's for the life of the author plus an additional 70 years, depending once again on the nation involved). Also, just b/c something may be royalty-free in one nation (ie., expired copyright so as to fall into the public domain, under Fair Use, a limited license to use, etc.) doesn't mean its not protected some place else. Again, very thorny issues, for which you really should seek proper legal advice. I see you're in Canada? Excellent. If you don't have legal representation already, might want to google and contact the IP/E-Commerce Law Center at Osgoode Hall Law School (they've exceptional resources available to you and everyone online). They've also a clinic, but better for you to give UBC's law clinic a shout. I don't know the extent of UBC's assistance, but they should be able to direct you to a licensed member in BC at the very least. (I don't specifically know anyone in BC that I could refer you to, sorry; but Osgoode and UBC are a good start, and should be able to assist and/or better direct you). Also, check this link out:
http://www.socan.ca/jsp/en/pub/contact/index.jsp It's to SOCAN, who ultimately handles clearances and royalties in Canada (clearing for digital use isn't all that simple, but there are always options and alternatives no matter what, and SOCAN can/does assist). I always recommend people seek proper advice before doing anything though, and trust UBC can direct you in that regard, as I assume by posting here you haven't got a lawyer already (and if you do, make an appointment). Seriously, learn how to do it right and consider your options, including the commons idea above etc. which is a good idea, I agree. There are a lot of musicians out there looking to earn a living who own their material 100% and are likely to be very happy to hear from you, but remember, don't sign anything until you get proper advice (seriously, it's worth it). Best of luck with your project.
tl/DR: Osgoode Hall has immense resources on line available, and SOCAN clears music in Canada, but digital rights (online use of music) is very complex, involving many issues, and for which you should seek legal advice.
