In good poetry, nothing is by chance. Every technical gesture justifies itself thematically. Any technicality that one can detect in good poetry is occurring exactly when something thematic is very important. It can occur in a new direction in the theme, in the introduction of the solution, or in the introduction of a character that is going to resolve the problem. That is where invariably the poet produces the metrical substitution.
The most prevailing line of verse in English prosody is the iambic pentameter. In a sonnet the sound pattern will be the same, which could make it terribly monotonous. So, the poet produces what is known as Metrical Substitution, also called metrical variation, for a number of reasons. One of them is to vary the rhythmical pattern to produce excitement and action in the reader’s ear. So in a sonnet with the first three lines in the same rhythm, and in the beginning of the fourth line, for example, the poet may produce the metrical variation and may introduce a trochee at the initial position and then, go back to the pattern. So the metrical substitution is a deliberate breaking of the pattern, and the pattern is invariably the iambic pentameter. So the poet establishes the iambic pentameter, as that the incantatory pattern and then the poet deliberately breaks that pattern to produce variation, surprise, excitement.
Usually in sonnets, the first stanza introduces the problem, the second stanza complicates the problem, and the third stanza further complicates the problem. Then the solution to the problem comes in the final couplets. And it is usually there in the initial foot of the final couplet – right when the poet is introducing the solution, that he produces the metrical variation. Other times, they will produce it in the beginning of the third stanza, and it is called, in the sonnet, the volta, or the turn, because it is there that the argument turns. So, the metrical substitution is never by chance. If one identifies the metrical pattern, and later there is a breaking of that pattern, invariably one will discover that, there, something very important thematically is taking place.
John Keats’ sonnet On Sitting Down to Read King Lear Once Again, written in 1816, is not different. The poem presents Keats’ relationship with the Shakespearean drama King Lear and how it relates to his own struggle with the issues of short life and premature death as main theme. It is formed of three quatrains and one couplet, and presents metrical variation in at least three moments in the poem. The first and the second moment of metrical variation are produced by the poet for (apparently) the same reason: rhythmical variation, and the third metrical variation, a turn of argument.
The first moment appears in the second line of the first quatrain, changing the metrification from iamb to trochee as follows - O gol / den-tongued / Romance, / with se / rene lute! /Fair plum /ed sy / ren, Queen / of far- / away! - The second moment of metrical variation appears in the first line of the second quatrain, breaking the pattern since the reader has to obey the punctuation as follows - Adieu! / For, once / again, / the fierce / dispute. And, finally, based on my interpretation of the sonnet, the third metrical variation will occur in the thirteenth line of the poem, which is the initial foot of the final couplet. In this point, the poet produces a turn of argument as if he had found a solution for his problem as follows - When through / the old / oak for / est I / am gone, / Let me / not wan / der in / a bar / ren dream:/ But, when / I am / consumed / in the / fire,/ Give me / new phoe / nix wings / to fly / at my / desire. In other words, I do not want to be forgotten, so when my time comeS, keep me alive through my writings, because doing so I will never be forgotten. The sonnet analyzed is In iambic pentameter, except for the last verse, which is an hexameter. Keats’ On sitting down to read King Lear once again rhyme scheme for the first quatrains is ‘a b b a a b b a’, the third quatrain rhyme scheme is ‘c d c d1’ and the couplet rhyme scheme is ‘e e’. It also presents assonance in the first quatrain – golden-tongued Romance…- and an in the third quatrain – through the old oak forest.