The notebook held four bars of music and the instruction wait for the answer. Milo could play the notes but did not recognize the tune. His grandfather had carried the notebook on walks through Slate Steps until his death.
A neighbor heard Milo practicing and answered with four different bars. Her husband had whistled the response from their workshop window. The two men used the exchange to check whether the other was ready for their morning walk. Neither tune was a complete song.
The neighbor found her husband's matching notation in a drawer. Together, the fragments formed a pattern of question and reply, though no title appeared on either page. Milo recorded her humming both parts and wrote down the practical arrangement she remembered.
He did not begin whistling beneath the empty workshop window. The old exchange belonged to two people who were no longer there. Instead, he learned both parts and played them at a family gathering, explaining why the pause mattered. For a few seconds between phrases, everyone could hear the space that had once allowed another person to answer.