Three experimental studies suggest that music with more musical voices (higher voice multiplicity) tends to be perceived more positively. In the first experiment, participants heard brief extracts from polyphonic keyboard works representing conditions of one, two, three, or four concurrent musical voices. Two basic emotions (happiness and sadness) and two social emotions (pride and loneliness) were rated on a continuous scale. Listeners rated excerpts with higher voice multiplicity as sounding more happy, less sad, less lonely, and more proud. Results from a second experiment indicate that this effect might extend to positive and negative emotions more generally. In a third experiment, participants were asked to count (denumerate) the number of musical voices in the same stimuli. Denumeration responses corresponded closely with ratings for both positive and negative emotions, suggesting that a single musical feature or percept might play a role in both. Possible roles for both symbolic and psychoacoustic musical features are discussed.