O is both the human mouth, and an ungoverned sound from deep within. Oh is the shallow, breathy exhalation of a Valley Girl with a new retainer.
O claims space/Oh collapses.
O is forceful, a stiff-arm/Oh is ineffectual, and flitters.
O is emotive/Oh so bland,unlike the quixotic ampersand.
[Write poem using both ampersand and Samarkand. Go!]
O stops time/Oh dribbles interminably.
Even as colloquialism, Oh has been irredeemably Simpsonized by D’oh.
On O’s resonance with the full moon, see the New Yorker cover.