We explored the role of lyrics and melodies in conveying emotions in songs. Participants rated the intensity of four types of emotions in instrumental music or the same music paired with lyrics. Melodies and lyrics conveyed the same intended emotion in Experiments 1 and 3 but were mismatched in Experiments 2 and 4. The major findings in Experiments 1 and 2 were that lyrics detracted from the emotion in happy and calm music (positive emotions), but enhanced the emotion in sad and angry music (negative emotions). In all cases, melodies of songs were more dominant than the lyrics in eliciting emotions. In addition, in Experiments 3 and 4, the emotion in the songs appeared to transfer, simply by association, to pictures of common objects arbitrarily paired with the songs.
Source: “Songs and emotions: are lyrics and melodies equal partners?” from Psychology of Music