How does one describe the sound of ice shifting in a plastic bottle?

The ice water doesn’t move in perfect time with the sway of the purse around it.  It is a step behind. It is a follower. Crystal clear water slides up the side, not quite reaching the black lid.  Winter sunlight shines through the hall windows and shines through the clear plastic bottle. The ice is porous from melting, from being made by an old freezer.  It’ll be perfect to crunch later on, if any of it remains after the water is gone.

Every step makes the water shift one step behind, makes the water swirl.  The ice is forced along in the constant changing current. Forward. Schlup.  Backward.  Schlap.  Forward.  Schlup.  Backward.  Schlap.

There is the rush of water.  Sch.

There is the dying of inertia before the lid.  Lup.

There is the rush of water. Sch.

There is the hitting of the plastic bottom.  Lap.

Forward.  Schlup.  Backward.  Schlap.  Forward.  Schlup.  Backward.  Schlap.

It is rhythmic.  It is musical. It is a reminder of time as the morning ice still sounds the melody in the early afternoon.   It acts as an echo to footsteps as they travel down the long hall.

Forward.  Schlup.  Backward.  Schlap.  Forward.  Schlup.  Backward.  Schlap.

The sound of ice shifting in a plastic bottle.