In Hart Crane's poem, "My Grandmother's Love Letters," I think there are several potential themes; we may find different messages based upon our personal experiences.
One theme may be that of change: it is inevitable. The speaker is confronted with the adult task of seeing to his grandmother's love letters stored in the attic, and he is hesitant to read them. Perhaps he is afraid that when he learns about the younger woman she once was, he will not longer be able to look at her the same way. These lines show that the speaker believes there is enough room for memories, especially those of his grandmother. And in this place, there is room for her words:
Yet how much room for memory there is
In the loose girdle of soft rain.
There is even room enough
For the letters of my mother’s mother…
Another theme is that we are forever confronted with decisions that can change us: we need to decide what the potential outcomes are, to move cautiously, and be prepared for the unknown as we search out territories new to us. In these lines, the author relies on the adult within to take care of his grandmother (even of her letters and his memories), explaining the "new" way of the world to her—but he is still nervous, and stumbles, as he moves to help his grandmother in these "new territories:"
Yet I would lead my grandmother by the hand
Through much of what she would not understand;
And so I stumble.
The theme of having enough love in our hearts to accept all sides of a person is important: the comfortable things, and those that may confuse us. This line represents the speaker's need to confront who "Elizabeth" was, and the memories that have waited so long to be found; this unknown "Elizabeth" causes worry to the speaker, but he wants her to remain his grandmother:
For the letters of my mother’s mother,
That have been pressed so long
Into a corner of the roof
We might see another theme in keeping our memories alive, and not allowing words or obstacles that are unimportant to cause us to lose sight of those memories just because we come to see a person in a new light. The poem begins with optimism—the stars are hidden, but not the memory—there is room enough to protect those memories, and keep them whole:
There are no stars tonight
But those of memory.
Yet how much room for memory there is…
We could also see the theme that we can never really know a person. We can know things about a person, but everyone keeps a private piece of self hidden inside. The speaker wonders how he will learn about his grandmother…he must openly review the past; can he go places in his memory and come back with enough knowledge of her, to better know her?
And I ask myself:
“Are your fingers long enough to play
Old keys that are but echoes:
Is the silence strong enough
To carry back the music to its source
And back to you again
As though to her?”The last thing the speaker hears is rain on the roof, "with such sound of gently pitying laughter." This could be the author's realization that as he worries over who his grandmother really is, the concern is only his. The "gently pitying laugher" may be symbolic of his grandmother's knowledge of what he is searching for, as she may have searched for some answer in her day: the laugh is gentle, which denotes caring, while the laughter is also pitying as she knows he must search, and she is sorry she can't help by sharing what she has learned about life.