The idea of the musical glass came from the Crow whose poem you can read here. This is an attempt to tease out the idea in a different way.
The glass is humming in my head,
thrummed by a moistened finger,
idly following the tune,
the hand that pointed from the cloud.
Crystal fills with starlight, moonlight,
gathers silver chords glissando,
building music of the spheres.
The hand with moving finger falters,
having lost its song moves on
to write its orders in the wind.
Wind and water rise and turn
about the pristine crystal rim,
while the greybeard stops his ears.
The glass still hums its monologue,
for who can stop the wind, the tides?
No finger pointing from the clouds
can silence music of the stars
and tell the music of the moon: be not.