Classical music lost ground in the 20th century to the music of the dispossessed, whether American blues, the Gypsy jazz of Paris, Argentine tango or the yearning strains of Greece, called rebetiko. David Prudhomme’s graphic novel tells a story about the Athens underclass of the 1930s and the musicians who provided entertainment and ecstasy. Prudhomme draws his novel from tales circulated about real musicians, painting their nightclubs in dark chocolate tones and the dawn in gorgeous shades of blue. “How can you sell music? You can’t sell the wind! It disappears!” one of the players exclaims in the last echo of a fading age.