Completed in 1905 as one of the earliest large-scale works that Webern produced under Arnold Schoenberg’s tutelage, the Langsamer Satz for string quartet has been deemed ‘disarmingly conventional’ (James Beale), as no more than an ‘exercise’ (Walter Kolneder) through which the young composer honed his compositional craft. Challenging this mode of interpretation, this chapter attends to what is perhaps the movement’s most salient feature: its exuding sense of lyricism. Through a combination of voice-leading and transformational perspectives, it is argued that the lyricism pervading the work is rooted in an audacious dual-tonic practice. The movement’s tonal disposition is further illuminated with reference to contemporaneous debates that erupted in post-Riemannian music-theoretical discourse, especially Georg Capellen’s conception of Doppelklänge (‘hybrid chords’). The picture emerging from these considerations is that the Langsamer Satz features compositional strategies that seem rather unusual for an ‘exercise’, and which cannot be explained with reference to Schoenberg’s musical thought alone.