How did Romantic composers combine leitmotifs through counterpoint?

Romantic composers utilized counterpoint to weave together leitmotifs, transforming them from simple representative themes into complex, interwoven musical structures that carried both emotional and dramatic significance.1

In the music dramas of Richard Wagner, this technique reached a high level of sophistication. Wagner balanced the vocal "speech-song" (Sprechgesang) against an orchestral accompaniment where multiple leitmotifs were set in counterpoint against one another. For example, in Tristan und Isolde, he layered these themes to create a "counterpoint of connotations," where the interaction of motifs simultaneously expressed conflicting emotions and dramatic ideas. Similarly, in the Prelude to Act III of Siegfried, he cast the "Need of the Gods" motive against the "Valkyries" motive.1

This approach extended to instrumental music as well. Hector Berlioz combined the "Dies Irae" plainchant with the "Round of Sabbath" theme in his Symphonie fantastique, while Gustav Mahler later employed complex webs of interwoven motives, often highlighting individual themes through solo instrumentation.1