In four experiments, we examined whether facial expressions used while singing carry musical information that can be "read" by viewers. In Experiment 1, participants saw silent video recordings of sung melodic intervals and judged the size of the interval they imagined the performers to be singing. Participants discriminated interval sizes on the basis of facial expression and discriminated large from small intervals when only head movements were visible. Experiments 2 and 3 confirmed that facial expressions influenced judgments even when the auditory signal was available. When matched with the facial expressions used to perform a large interval, audio recordings of sung intervals were judged as being larger than when matched with the facial expressions used to perform a small interval. The effect was not diminished when a secondary task was introduced, suggesting that audio-visual integration is not dependent on attention. Experiment 4 confirmed that the secondary task reduced participants' ability to make judgments that require conscious attention. The results provide the first evidence that facial expressions influence perceived pitch relations.