Nigh Fast As Echoes Die

When list'ning to a brilliant, glorious song,
Within our minds it sound--rebounds--and sings,
And in the moment seems to so prolong:
The tune--the whole--in panorama rings. 
But, when it ends, all suddenly is gone,
For mem'ry fades nigh fast as echoes die,
And when we strain to then recall the song,
We hear the empty strain of open sky. 
We're left with halting fragments--ghosts of tunes--
And mem'ries only of remembering;
The notes forgotten: new and distant moons,
And nothing comes when we 'gain try to sing. 
To keep the mem'ry of that song alive,
To listen to it oft we oft must strive.