I've been noting lately that one of Eliot's loved images was the 'dying fall', which appears in Prufrock and also in Portrait of a Lady, being always related to voices or musicality. In Portrait of a Lady it's written between inverted commas ("dying fall"). Here it is referred to the music that's being played and also to the lady's destiny ('Now that we talk of dying'); whereas in Prufrock, it's referred to voices 'dying with a dying fall' as opposed to the 'music from a farther room'.
But 'dying fall' is always accompanied by another 'dying' used singularly.
Translating the same phrase within two different poems, I found that surprisingly I cannot translate them with the same Italian expressions. For instance, as for the voices, 'fall' can also be assumed as a precise vocal intonation, whereas a 'dying fall' in music would be more likely translated through a technical expression (i.e., 'diminuendo' and 'morendo'), which are typical of classical scores. Of course, 'morendo' means 'dying', as well.
But I perceive a subtle difference between the two phrases in English, also, which lies beyond the contextual reference.
 
Cheers --
Sara