Do the languages that people speak affect the way they think about musical pitch? Here we compared pitch representations in native speakers of Dutch and Farsi. Dutch speakers describe pitches as ‘high’ (hoog) and ‘low’ (laag), but Farsi speakers describe high-frequency pitches as ‘thin’ (naazok) and low-frequency pitches as ‘thick’ (koloft). Differences in language were reflected in differences in performance on two psychophysical pitch reproduction tasks. This was true even though the tasks used entirely nonlinguistic stimuli and responses. To test whether experience using language changes pitch representations, we trained native Dutch speakers to use Farsi-like metaphors, describing pitch relationships in terms of thickness. After training, Dutch speakers’ performance on a nonlinguistic psychophysical task resembled native Farsi speakers’. People who use different space-pitch metaphors in language also think about pitch differently. Beyond correlation, language plays a causal role in shaping mental representations of musical pitch.