ring down the curtain (on), to

ring down (or up) the curtain

mark the end (or the beginning) of an enterprise or event.
The reference here is to the ringing of a bell in a theatre as the signal to raise or lower the stage curtain at the beginning or end of a performance. Compare with bring down the curtain on (at curtain).
See also: curtain, down, ring

ring down the curtain

To end a performance, event, or action.
See also: curtain, down, ring

ring down the curtain (on), to

To bring something to a conclusion. In the nineteenth-century theater a bell rung backstage was often used as a signal to lower the curtain, signifying the end of a scene or act. Thackeray recorded it thus (The End of the Play): “The play is done, the curtain drops, slow falling to the prompter’s bell.” It was transferred to other kinds of ending by the early twentieth century.
See also: curtain, down, ring