"The King of Swing" is a phrase that refers to a musician who is adept at playing swing music. Synonyms for this expression could include "Swing Master," "Swing King," "Swing Legend," or "Swing Icon." Other phrases that could be used to describe a musician's proficiency in playing swing could be "Swing Virtuoso," "Swing Prodigy," "Swing Expert," or "Swing Maestro." Each of these variations emphasizes the artist's profound understanding and mastery of the genre and their ability to bring the energy and rhythm of swing to life through their music.