"I've always wondered what the legal specifics of using the included loops and samples in Logic, Reason etc are [...]" I cannot speak for all music composition

"I've always wondered what the legal specifics of using the included loops and samples in Logic, Reason etc are [...]" I cannot speak for all music composition hardware and software, but from my experience, the primary constraints on the products that I use (e.g., Reason) are generally two-fold: 1. Packaging or recording factory-included loops or sounds for the purpose of re-distribution as a stand-alone audio library is prohibited. 2. Using factory-included sample tracks for commercial purposes is prohibited. Otherwise, factory-included loops and sounds can be used commercially in your compositions. Again, the above are just my experiences. However, as noted by leviathant's comment with the Korg ER-1 experience, it is always a good idea to read the license agreement.