The Lone Instrument: Musical Solos and Sadness-Related Features

Given the extensive instrumental resources afforded by an orchestra, why would a composer elect to feature a single solo instrument? In this study we explore one possible use of solos—that of conveying or enhancing a sad affect. Orchestral passages were identified from an existing collection and categorized as solos or non-solos. Independently, the passages were characterized on seven other features previously linked to sad affect, including mode, tempo, dynamics, articulation, rhythmic smoothness, relative pitch height, and pitch range. Using the first four factors, passages were classified into nine previously defined expressive categories. Passages containing acoustic features associated with the “sad/relaxed” expressive category were twice as likely to employ solo texture. Moreover, a regression model incorporating all factors significantly predicted solo status. However, only two factors (legato articulation, quiet dynamics) were significant individual predictors. Finally, with the notable exception of string instruments, we found a strong correlation (ρ = .88) between the likelihood that a solo is assigned to a given instrument and an independent scale of the capacity of that instrument for expressing sadness. Although solo instrumentation undoubtedly serves many other functions, these results are consistent with a significant though moderate association between sadness-related acoustic features and solo textures.