Epitaph
narrow spot
A grave. The physical smallness contrasts with what comes next—the chest cavity that held a huge spirit.
emerald seams
The grass growing over the grave, but 'seams' suggests stitching—like the body is sewn into the earth.
as far as cannon dwell
Military language. This is a soldier's grave—fame measured by the reach of warfare.
deathless syllable
The person's name lives forever. Paradox: the syllable is deathless, but the person is dead.