Tonal, Synthetic, Instrumental, Electronic, Analogue
If you're a musician, you might understand the descriptive words a bit more than if you're not. Let's just say that these are tonal sounds that were created with both electronic (digital) synthesizers as well as with analogue synthesizers. Most are rather abrasive, but also ambient, if that makes any sense. As far as usage, I'm afraid, once again, I'll have to leave that completely in your capable hands.