In March 1931, the 47 year old Eliot wrote to Stephen Spender: "I have the A minor Quartet (the Op 132 quartet, one of the 6 late quartets of Beethoven) on the gramophone, and I find it quite inexhaustible to study. There is a sort of heavenly, or at least more than human gaiety, about some of his later things which one imagines might come to oneself as the fruit of reconciliation and relief after immense suffering; I should like to get something of that into verse before I die."
Two years later Eliot wrote that he wanted to get "beyond poetry, as Beethoven in his later works, strove to get beyond music". It would seem he was seeking an ineffable understanding that words and music can only point to.
Both men had suffered hugely in their lives; Eliot with his turbulent marriage to Vivienne and Beethoven with his deafness. Both men sought a solution to their struggle and found it through faith; Beethoven was a Catholic and Eliot had converted to Anglicanism at the age of 38. Eliot makes frequent Biblical references in the Quartets and directly quotes Christian mystics such as Julian of Norwich.
Beethoven, writing the Op 132 Quartet in 1824 at the age of 54, was recovering from a serious bowel condition from which he had nearly died. As a result, he entitled the slow movement (the 3rd of 5 movements) "a song of thanksgiving ... offered to the divinity by a convalescent in the Lydian mode", and the second section of this movement bears the inscription: "Feeling new strength." The movement juxtaposes his hymn of gratitude with a sense of new found vigour.
Both men were also drawn to Eastern scripture.
Beethoven had jotted down in his diary a line from the Rig-Veda commentary in which God is described as being "free from all passion and desire". Eliot expresses similar sentiments in his poem:
The inner freedom from the practical desire
The release from action and suffering, release from the inner
And the outer compulsion, yet surrounded
By a grace of sense, a white light still and moving.
A study of the Four Quartets points to many ways in which Eliot seems to have drawn on Op 132. The 4 poems are in 5 parts as Op 132 is in 5 movements. Similarly the 5 parts reference the length and style of Beethoven's musical form, even mimicking the 'sonata form' structure of Beethoven's 1st movement in the first part of each of Eliot's quartets. Eliot also plays with musicality in multiple ways such as rhythmic devises and the musical sequencing of thoughts and phrases. He even alludes to the 4 instruments of Beethoven's quartet by creating different 'voices'. Eliot has written that he found it helpful to beat a drum as he composed; rhythm and speech were fundamental to his poetry. It would seem that Eliot conceived poetry as something to be heard rather than something to be read and that he, in his own way, sought to make music.