Mastering a finished mix for release

For self released music the automated pass has become the default, because a mastering engineer costs a few hundred euros a track and takes days, and the service costs a subscription and takes minutes. What it does is measured and narrow, setting level, balancing the spectrum and controlling dynamics against a target derived from a catalogue of references. Engineers kept the work where the record matters, a catalogue reissue, an album that has to hold together across forty minutes, a vinyl cut where the medium imposes limits the software does not know about. The judgement being bought there is a reading of what the record is trying to do, and a person on the other end of the argument.