As the first systematic 12-tone composition, the Petrarch movement from Schoenberg's Serenade has been associated with ‘newness’. Yet it has conservative features. Medieval notions of isomelody and isorhythm, as well as Renaissance concepts of paralleling a poem's prosody and emotional content, are here. Moreover, 12-tone composition itself is an evolution of ‘Chromatic Completion’ – a technique already flourishing in Haydn and Mozart. Ultimately, what matters most is Schoenberg's understanding of the aesthetics of love. To appreciate this, the essay makes use of the philosophy of Aesthetic Realism, founded by the great American poet and scholar Eli Siegel. Beauty, he taught, is ‘a making one of opposites, and the making one of opposites is what we are going after in ourselves’. And love, he explained, has an aesthetic basis: it is ‘proud need’. This essay indicates technical ways in which Schoenberg illustrates the truth of these concepts.