Shirley's point about the poisonous influence of theatrical technique is spot on. It's a put-down for all the forms of spontaneous delivery those songs traditionally got: if you haven't been to drama school you've got no business singing a lullaby to your infant.

The analogue for instrumental tunes is what jazz-trained people do to them. Music that developed as something for working class gatherings to dance to, played by one or two musicians using whatever technique would do the job of getting their feet moving, gets dressed up in syrupy harmonic arrangements designed to anaesthetize the besuited white American elite in sleazy cabarets.