Actually, we all know the answer from what we're doing.
But first I want to come back on a quote from yesterday. A lot of forum members regularly post their own version of existing (classical) works. I guess (and I count myself in) they are mostly doing so to gather more skills in using the rich VSL libraries. It goes without saying that this takes a long and intensive learning process. It's a lot easier to start with good existing music. Then one doens't have to bother about structure, harmony, progressions, rhythmic patterns... It's already there and it is excellent as it is. The only matter remaining is the performance (interpretation and execution, after the meticulous search for the most apt articulations). Of course the ultimate goal of our labour (and that is what it it is) consists of creating our own compositions and consequently perform them as a kind of replacement/alternative for the barely existing possibility of a live performance.
To the point now. My answer is simple: we are composers, musicians, creating in any manner new our traditional work and want it desperately played for an audience. Music is communication and communication needs at least an ear to listen to it. Comments afterwards are welcome, but not necessary. That's why we chose the difficult alternative of virtual music. (I hate the senseless word 'mockup' in this context. There's no mockery involved here.) Therefore we necessarily have to be technicians imposing ourselves to deal with knobs, sliders, CCs, key switches, etc. Sculpting sounds/instruments is not a composer's business, but do we have another choice? We can sit back with our paper versions until a fairy comes down and takes us to the musical heaven were every note will be performed brilliantly. Alas, that can be centuries beyond our graves, or...never.
On the other hand, let's be extremely happy that we live in such wonderful times where all this is possible. I can still see myself writing hundreds of hanwritten scores and multiplying them to be performed with my chamber orchestra, until... until the first computer entered the house. The notation program MusicPrinter Plus did the job and played back everything notated. Wasn't that wonderful? And things went fast. Some 20 years later, we have a more then decent philharmonic orchestra at our fingertips.
Are we performers? Some are, some aren't, depending on the point of view. Is a performer someone playing in all the notes (in a concert-like way)? Or is he the patient manual enterer of a note-by-note score? One is a lot faster than the other, but the final result can be the same after hours/days of tweaking. Is the computer the performer (with VSL and other libraries)? Definitely not. A machine doesn't perform, it simply acts as a transmitter of human creativity which will always come first. Can a computer compose? Maybe, if composing limits itself to recreating technical rules and conventions (harmonic structures, strict musical phrases, guitar chords, pitch bound accompaniments...) neatly entered again... by humans in programs.
So I think we're some kind of octopusses with a certain skill at each arm and we try to leave one arm free to conduct our work. At least in our heads.
Jos