I'm about to start teaching myself to use Cubase, but before I do I need to understand a fundamental thing. I know the software has phenomenal power to alter and arrange sound, but where do the sounds originally come from? Do you have to record instruments/vocals/noises and then load them in, or can the software create the sound itself virtually?
Do you have to record instruments/vocals/noises and then load them in, or can the software create the sound itself virtually?
Yes to both. You can basically work either with a sampler (which contrain prerecorded samples of different instruments, in different pitches, spread out over the keyboard) or with synthesizers which more or less creates the sound you want on the spot. Both of these technologies are implemented as plug-ins, for example as a VST.
Both approaches will work. In fact you can easily create music inside Cubase without importing or recording any sound. I.e. you can open a midi editor in Cubase and manually insert notes, modify their length/volume/pitch, and then route this midi track into an "instrument", that generates sound from midi. For example, Steinberg Synth HALion, which comes with Cubase(at least it did with my Cubase 6 LE)