The Happy Xylophone: Acoustics Affordances Restrict An Emotional Palate

In many ways, the structure of music resembles that of language, including the acoustic cues used to communicate emotion. In speech, sadness is imparted through a combination of low fundamental frequency, dark timbre, and a slow rate of articulation. As the acoustic properties of the xylophone are not conducive to mimicking these cues, it seems to follow that composers would avoid attempts to write "sad" music for it. We investigated this idea by comparing the repertoire of the xylophone with that of the marimba -a similar instrument whose acoustic structure permits a greater variety of timbres, pitch heights, and tone durations. An analysis of repertoire drawn from the Percussive Arts Society database of recital programs reveals that 60% of the tonal marimba examples surveyed were written in minor (nominally "sad") keys. In contrast, a parallel analysis of xylophone literature found minor keys used in only 6% of the examples surveyed. Further investigation revealed that the only examples of minor-key xylophone compositions included in this survey are in fact typically performed on the marimba. The avoidance of minor-key works on xylophone by both composers and performers is consistent with the idea that instruments restricted to producing tones with short durations, bright timbres, and high pitch heights are unable to mimic the speech cues used to convey sadness and/or depression.