& cf. JL today for a different angle on "abstraction".
The painter's abstractions are "concrete conceptions" of color, line, shape. If we go back to Mandelstam's idea of poetry's double thread - the impulse and the medium - we can think of the formative impulse as abstract (logical, constructive), and of the medium as concrete (a fluent song, a dramatic design).
In poetry's case the medium is so different from that of painting (or music, for that matter). It is the word. In Mandelstam's sense, the (poetic) word is a "plow, turning up the deep layers of time". How so? Because, for one thing, the word is the intimate expression of human consciousness - and it is lasting. Thus it forms a bond between human beings of different places and epochs. "I don't want Ovid in translation; I want the living, breathing Ovid." (Mandelstam again)
This archaic, perennial aspect of the poetic medium is part of what I meant by tradition as an objective reality (the bees' hum, the ongoing conversation). Thus poetry displays two kinds of fluency : sonic and "chronic".
It is precisely the modern-postmodern emphasis on breakage, dissonance and iconoclasm - & the banal-commercial-industrial iterations of same - which make this special fluency of the poetic medium difficult to recognize or value.