The Sliding Head
Is formed by a sequence of slides, i.e. downward pitch movements, associated with each fully stressed syllable of the head.
It has a jumpy, or wavelike, character. Such an effect is due to the pitch contrast between the end of the preceding stress-group and the beginning of the following: the latter is higher in pitch as a result of a downward pitch movement over the preceding stress-group, realized either as a glide on the stressed syllable (when there aren’t any unstressed syllables following) or as a jump between the stressed syllable and the following unstressed ones.
(Jumpy) We ↘haven’t been ↘hearing from him for ̀ages.
(Step-like) We ̍haven’t been ̍hearing from him for ̀ages.
Partially stressed syllables behave in the same way as the unstressed syllables: they gradually carry the pitch down, so that in a one-peak head, where full stress is given only to the first word (national, as a rule) while the other prenuclear stresses are partial, the overall pitch pattern is falling rather that sliding:
You ↘can’t ↘wait here all ̀ ́day.
Meaning: lively, expressive conversation and in reading emotionally colored texts.