You could tag the Album Artist field with the value Freemasons. The Album Artist (auto) field would then automatically show the same value. If you use the Album Artist (auto) field as the main artist definition in your views the album tracks will be correctly grouped. If the Album Artist value is not yet tagged the automatic value is (multiple artists) for albums that contain various artist values.
A search for Sophie Ellis works even if she included only as a part of the name string, but in addition you could create an additional semicolon delimited list field for storing several artists per each track. You can create new views that include this custom field.
Regarding "without using custom metadata", the basic, default fields are closely tied with the online CD database and there is no simple way to change the established db structure. However, you can use all kinds of custom metadata in MC. It is one of the advantages you have, not a problem.