Why are music production and audio processing software so much more skeuomorphic compared to other user interfaces today?
Most other computer UIs have shifted toward minimalism and flat design, yet audio production software still looks realistic (with knobs, buttons, instruments, etc.) What's the reason for that?
Because a lot of it relates to real-world counterparts.
This creates an instant bond with the controls, and allows for easier reading of purpose and meaning.
More specifically, and to answer Nick Coad's comment; the reason it's more prevalent when mixing music, is because there is more UI than in possibly any other job.
To learn two separate skill sets, would be a bit unwieldy.
I am a former recording engineer and a current UX designer. I think skeuomorphism initially allowed engineers to transfer deeply ingrained behaviors from the physical interfaces they were trained on to a very different set of digital tools. It's the same role skeuomorphism has always played in digital interfaces.
The reason it's stuck around longer in music production software is probably due to the highly nostalgic nature of the business. For many in the business, analog tools and sound quality are still considered the gold standard. Digital tools are much cheaper and offer a more efficient workflow, but anything that connects them to the tools of the recording industry's heyday was a win.
That industry is finally reaching a tipping point where more of the older engineers—the ones who were actually trained on physical interfaces—are being replaced by younger engineers who have learned or taught themselves on Protools or Logic and the like.
As an amateur DJ and music producer I can relate to this. There are two reasons. One in terms of learning curve and the other in terms of cognitive effort.
The physical interfaces used in music hardware equipment has been around for a very long time, therefore the user patterns related to interacting with these hardware are solid and attempting to change them runs the risk of being alienated by what the industry is used to. Even modern hardware (e.g. surface pro knobs) follow these analog-inclined UI patterns.
The other reason is because digital UI interaction is still not exactly direct because of the limitations of current touchscreen technology. Meaning the user has to look at the screen while pressing the mouse or track pad to see the visual output and listen to the audio output at the same time. In terms of cognitive effort this is a lot compared to directly manipulating real world faders and knobs while listening to the audio output. When touch technology has matured to the point that direct interaction on the screen is accurate and gives feedback to touch perhaps audio
Also as Refe mentioned, in the industry in general there's the shared belief among most that old is gold and to always stick to roots, which is why even musical instruments haven't changed.
Historically, it would have been to make the transition from real-world recording studio components to their virtual ones easier for reluctant producers and musicians.
These days there's probably a lot more "that's the way it's done" inertia although, if you look at more DJ oriented software it looks more contemporary than
The article "Beyond Skeuomorphism" offers a detailed look at the evolution of music production interfaces. While it doesn't go into detail on knob skeuomorphism, it does mention that Steinberg's Cubase VST popularized the skeuomorphic plugin design.
It seems that it stuck around. Other software categories don't seem to have such a strong history of such a high level of skeuomorphism.
However, the trend does seem to be slowly receding. For example, if you take a look at the latest version of GarageBand on both macOS and iOS, you'll see that skeuomorphism is toned down quite a bit.
It's important to mention that piano keyboard interfaces emulate physical interfaces as well. The article mentioned above also goes into detail about alternatives to keyboard interfaces and how they haven't proven to be successful because of a higher learning curve and the inability of audiences to connect with instruments that they don't understand the manipulation of. (In worst-case scenarios, the audiences become so disconnected that the process of making music looks the same as if the artist was playing a recording.)
