Virtual instruments triggered by MIDI have been able to replicate orchestral parts for some time, but there's still an art to making them sound realistic. This isn't always to do with the samples, but with the way you program them and a key part of this is controlling velocity, which you can do in your DAW. In this video from the course Orchestration 301: The MIDI Orchestra - Enhancing Realism, Peter Schwartz shares his pro techniques for making your virtual orchestral tracks sound believable.
Peter explains that when working with orchestral instruments, you very often need to simulate the human element of a real player, who will not play every note with exactly the same force or in the same way. The best approach to simulating this using MIDI is to vary the velocity of different MIDI notes within a part. This can be done using manual MIDI editing in the velocity controller lane, where you also need to know about the different velocity curves available on your MIDI controller. Using practical examples, Peter shows you the best way to achieve the results you need. Check out the full course for a complete guide to making orchestral DAW tracks sound great!