Do major-label artists have any creative freedom, or is almost everything they do controlled by their label? If not, what do they have control over?

For example, artists like Rick Ross and Jeezy are usually credited with at least having good beat selection. Are they actually the ones who pick the beats, or are they given a selection of beats that fits their image that the labels are trying to sell?

I've never known exactly how much control labels have over bigger mainstream artist and what parts of a project are genuine.