William Rothstein's (1989) seminal work on phrase rhythm has been foundational for scholars who study phrase expansion using Schenkerian principles, such as David Beach (1995), Charles Burkhart (1997), Joseph Kraus (2009), and Samuel Ng (2012). Other scholars consider phrase expansion from the perspective of William Caplin's (1998) form-functional theory, such as Janet Schmalfeldt (1992, 2011) and Steven Vande Moortele (2016). Both groups tend to emphasize more structural concerns. Recent theories of musical meaning, however, challenge analysts to consider phrase expansions through a more expressive lens. This presentation engages with that challenge using the metaphor of musical motion, a concept that is informally present in myriad analytical writings, but which was formalized in work on conceptual metaphors by Steve Larson and Mark Johnson (2003). In particular, we introduce a category of expansion techniques called "alternative paths" in which a phrase deviates from its expected course toward a goal via the addition of new material. By defining the way in which the new material is initiated and concluded, alternate paths provide a more nuanced view of passages that might otherwise be captured under the more generic terms "interpolation" or "purple patch." We will demonstrate how our approach highlights the differences between phrase expansion techniques by revisiting the two instances of expansion that William Rothstein identifies in his analysis of Mendelssohn's Song Without Words Op. 19, No. 1. Following this discussion, we will show how our approach accommodates even extreme expansions like the 47-measure period that begins Mendelssohn's E-minor Violin Concerto.