In this video I discuss a way of thinking about rhythm but filling the 'empty space' between the notes of an existing melody or rhythm. You can call it a 'negative rhythm'. I've been using this in a piece I'm working on at the moment for the BBC Proms, which is called 'Sidechaining' and the negative rhythm idea is closely related to the technique of sidechaining found in Digital Audio software like Ableton Live.
The idea also relates to videos by two of my favourite YouTubers on the hypothetical subject of 'Negative Time Signatures'. Here are those videos: