Prior research has amply documented that happy music tends to be faster, louder, higher in average pitch, more variable in pitch, and more staccato in articulation, whereas sad music tends to be slower, lower, less variable, and more legato in articulation. However, the bulk of existing studies are either correlational or allow these expressive cues to covary freely, thereby making it difficult to confirm the causal influence of a given cue. To help address this gap, we experimentally assessed whether the average height (F0) of a pitch gamut independently impacts the perceived emotional expression of melodies derived from the gamut. Study participants rated the perceived happiness/sadness of a set of isochronous and semi-random tone sequences derived from the Bohlen-Pierce scale, an unconventional scale based on pitch intervals that do not appear in common practice music. Results were consistent with the notion that higher average pitch height communicates happiness and/or that lower pitch height communicates sadness. Moreover, they suggested that the effect is: (1) sufficiently robust to be detected using rudimentary melodies based on an unconventional musical scale; and, (2) independent of interval size.