2018 release. When Caroline Davis found out that her father had heart arrhythmia the news prompted her to do detailed research on the physical aspects of the human heart. It was with all of this in mind that Davis decided to compose pieces relating to the heart, whether it was an emotional connotation or the utilization of rhythms derived from heartbeats. Composing really helped to get her through much of her emotional transition. Heart Tonic finds Davis employing more standard jazz elements than much of her previous work, including formal harmonic changes and shifting meters.