Most key-labelled sample packs i have have the samples labelled eg Dm, E, Fmaj, Cmin or something like that.
Some packs just show uppercase letters though eg C, F, A, etc. No min or maj. No uppercase for major, lower case for minor, just uppercase letters. When i flick through those samples i am fairly sure these aren't all in a major key. If one is labelled C but sounds minor, does that mean it's actually Amin (ie the relative key)? Or is that not the key but rather the root of such a sample?
I mostly didn't use these kind of sample packs or just trusted my ears, still would like to know what you think?

 

For starters, you should never trust the keys shown in a sample pack any more than those shown by key detection software. Better to trust your ears. Why? Some of those sample packs are put together by people that have minimum or no knowledge of music theory, and even if they do, it is easier to use an automatic key detector for labeling hundreds of samples. The problem is that none of those key detectors are 100% accurate. There lies the problem. Some of the more accurate sample packs will explain their key labeling protocol but the majority does not. As I said, it is more accurate to rely on your ears as long as you keep in mind that humans don't always agree.

 

Last edited: Jul 14, 2019

Thanks but that I consider obvious. ; )
My q therefore still stands. I'll take a closer look at those samplepacks in question again and post examples.

 

No, from a music theory POV there is no way something labelled "C" would actually be in A Minor. All the theorists would die from cringing at the sacrilege that would represent.

As far as what's going on with those mislabled samples for real though, that's anybody's guess!

In general if the key is labelled as "C", that's understood to be C Major by default. You would see Cm or Cmin for the minor.
If it's labelled as being in a major key but you're hearing minor vibes from the sample, try to set up a simple minor chord from the same root as the sample and sound those notes as it's playing. If you transpose your chord around as you play (just using semitones, ignoring key), you might find some really cool major/minor contradicting feells, very musically useful even if it's not "in key" according to the label.

To free yourself from the tyranny of keys and modes completely when working with samples it might help you a lot to think of any key as two tetrachords stacked on top of each other, with a wholetone inbetween:

So with this little bit of knowledge, you can treat any key/mode as simply a root note and a couple mix'n'match patterns played relative to that root, allowing you to "go out of key" with what the sample says but still sound awesome as you go into keys and modes that are correct, even though you may not know their fancy names at the time. You can even go full Mozart and decide to change either the bottom or the top tetrachord mid-melody depending on the feeling you want, and amaze people.

In a sequencer this is simple to do. Ok, here I am on a C note that at this moment in the melody I want to be the root for things to revolve around... Now make four little notes off to the side to serve as a guide, using the mix and match possibilities shown above. That will be tetrachord 1, rooted on C. Make a second stack of 4 notes a whole tone above the last note of the first stack, and there you go, you just made a correct sounding mode or key, fully custom to your melody. Use those tones to build with. All while completely ignoring whether it's white keys or black keys, major or minor, or "mixolydian" it doesn't matter to you and you are not restricted to a single key only, since you work relative and can go into a new key/mode at any time you want to capture a different feeling...

 

Last edited: Jul 14, 2019

I've never faced that issue. I've bought sample packs from Cymatics, Mystic Alankar and Echo Sound Works and everything is labelled pretty well. Which packs did they not label stuff properly? But anyway, if the samples are good who cares haha?