Usually I simply reply on NetBSD's audio(4) system, which at the same time provides in-kernel hardware support, an in-kernel mixer able to manage multiple buffers at the same time, and a usersace sound API. The latter includes native OSS emulation for legacy programs, provides a command-line frontend, some sysctl hw.audio.* tunable parameters, and a virtual interface (/dev/audio) for libraries like SDL, OpenAL and portaudio, as well programs capable of streaming directly to it (patches for firefox, seamonkey, mpv, mpd, ffmpeg have been sent upstream to allow this).

You can think of it as alsa-driver + alsa-lib + alsa-utils + alsa-plugins.
Mixing at hardware level doesn't result in the same cpu overload as that experienced in Linux using dmix, so using it directly without a sound server is still a viable option in this day and age.
There's also a curses front-end for the mixer available in base, which is called aiomixer.

On Linux (Slackware), I transitioned from a pure ALSA system (with plugins) to pulseaudio a couple of years a go, due to the fact most applications were dropping alsa-lib support. It's not like I wasn't using pulseaudio in light of some philosophical stance, it was just habit. Also, I have a good amount of legacy hardware and will happily use i686 machines daily, where the few more megabytes of volatile memory taken by pulseaudio may actually matter. I experimented with sndio a bit on Void Linux, but found application support to be too limited. I haven't looked into pipewire yet as of today.


I do not generate music on *nix, but like to play with MIDIs on FreeDOS, using Voyetra Sequencer Plus GOLD, in conjunction with MPXPLAY, which, unlike most DOS software, supports AC'97 besides classic ISA sound cards.