Here are two renderings of the “Orchestral Polonaise”. The music is exactly the same in each excerpt. The first audio uses only the computer-internal sound libraries that come with the Finale notation software. This method of rendering took a few hours.
The audio below shows rendering done outside the computer, using hardware synthesizers and remixing. Time spent to multi-track record, mix, master was over 5 hours.
We certainly hear differences. Flaws are found in both. It happens that my hardware synthesizers are pretty old technology, as none are newer than 2000 vintage electronics. I find software synths have become very popular, considering the growing number of such offered.
While I strive to record the best representation of the score, investing over 5 hours using HW synthesizers is hard to justify on a regular basis. Computer sound libraries seem passable for certain pieces. Occasionally I use the HW synths so I am not forced to create a sound or instrument “from scratch”. The best rendering of any score is live musicians, of course. Also, my current manner of scoring is somewhat sparse when it comes to expression markings in the music. Then there’s the impact of mix-down, final mastering, audio effects and engineering.
There is another alternative I haven’t yet mentioned: professional computer sound libraries. It’s that reliable fact that “you get what you pay for”. The “Vienna Instruments Vienna Super Package” includes solo and section orchestra sounds, saxophones, various organ and keyboard sounds, and more. That bundle can cost over $10,000.00 US. Some of us amateur composers just don’t have deep enough pockets.