Importance of hummability

In a recent article in the Times, Matthew Parris wrote stirringly about the inspiration which may come from listening to buskers: ‘Amazing how a snatch of music heard in passing can lift the imagination and spirit.’ To him the essence of this snatch is hummable or whistle-able melody, and we are told that the ‘superior’ musicians who ignore such a simple ingredient are ‘the parasites on a beast whose lifeblood is melody’.