From what I've discovered, you can sample a synthesizer's sounds if the synthesizer produces the sound electronically, e.g. using base waves such as sine waves, triangle waves, noise, etc. An old example of this is the classic Moog synthesizer. Just like I can record my own samples from nature (e.g. water droplets) and maintain copyright over that recording.
However, if the synthesizer generates its sound by playing internally stored samples, then I can not simply sample these "as is" to be used in isolation.
However, arranging the sounds into a composition of my own, so as not to use the sounds in isolation, seems perfectly fine.
So in conclusion, I should not sample sounds directly from my Yamaha CS1x to use in my commercial game release.
- I can record my own naturally or electronically created sounds.
- I have found a web site which does permit use of their samples as is. However, you still cannot use the sounds in "isolation". They must be "synchronized" with other media, e.g. as part of my game, or similar for other productions. They give a good FAQ including a definition of what "synchronized" means. However, you have to pay a one off license fee to use the sounds.
Good to know !