Greenbaum's One Day for voice, vibraphone and percussion is a carefully-crafted work conceived as a pop song. The simplistic beauty of this work is created with a jazz-inflected vocal line - suitable for both and female or male singers - and is supported by a delicate accompaniment of alternately running and syncopated figures in the vibraphone, with subtle contributions from percussion (crotales, glockenspiel and cymbals). An optional harmony vocal line is also cued into the parts.