An online record label, Black Hoe Recordings, to be precise, release all of their artists work under a creative commons license...
So... Can I upload sliced samples of their songs onto freesound?
i don't think you can - i had the same question about free samples on cd's...
I think the general rule of thumb is "if you can sell it, you can post it on freesound."
So if you use royalty-free sounds in a soundscape/mashup thing, you can post that (I believe this is what Bram said.)
But most royalty-free stuff doesn't allow for RE-distribution of the unmodified samples, as this is how they make their money.
I can't get on the website you linked to so I don't know which Creative Commons license it's under, which is very important. If it's an attribution license, you might be able to, and if the license allows you to transform the work (but is not share-alike) then you can post your derivative work.
Of course, you can also get permission directly from the author/rights holder to post it on freesound under the sampling plus license.
I'm emailing the big cheese
as halleck says, it depends on the license...
give us an example of a song (with it's license) and we'll say if it's ok to upload slices.