Do audio interfaces work on Linux?

Audio on Linux runs through ALSA, the Advanced Linux Sound Architecture, which provides the sound and MIDI layer for the system and covers everything from consumer sound cards through to professional multichannel interfaces. On top of that sits a sound server that handles routing between apps, and modern systems include one that supports low latency work rather than treating it as a special case.

The dividing line for hardware is class compliance. A class-compliant interface describes itself using a standard the operating system already understands, so it needs no software of its own. The easy test for this is the Mac test: if the maker says the interface works on macOS with no driver download, it is class compliant and Linux will see it too. Many popular interfaces are in this group, and a great many USB microphones and small two-input boxes are class compliant by design.

Interfaces that come with a Windows driver disc or a required download are the gamble. Some have been supported by work done in the Linux kernel anyway, and some have not. This is not something to guess at, because an unsupported interface is not partly broken, it simply does not appear.

Two things tend to be worse than on Windows even when the interface works. The maker's control panel, the one that does the internal mixing, the monitoring blend and the onboard effects, is a Windows program and generally will not run. Sometimes those settings are stored in the hardware and survive, and sometimes you lose access to them. The second is plugins. Windows VST plugins can often be made to run on Linux, but it is extra work and the ones with heavy copy protection are the least likely to cooperate.

Basic MIDI keyboards and controllers are far simpler. Class-compliant USB MIDI is standard and those normally just appear.