The musicians say “When a marriage happens between a lyric and a melody, only then a true song is born”! A proper song should express the true meaning of its lyrics through the movements of its melodic structure. “Which impacts more: Melody or lyrics?”—The answer is still unknown. The present work explores the acoustical contribution as well as the neuro-cognitive impact of lyrics in different genres of songs evoking contrast emotions. Four songs of two different genres (i.e., two songs from each genre depicting opposite/contrast emotions: joy-sorrow) were recorded from a trained musician who was asked to consecutively sing (with proper meaningful lyrics) and hum (without using any lyric or meaningful words) the songs, the obtained audio signals were later put to acoustical analysis. Later EEG signals were recorded for five naïve participants with different sets of song-humming (i.e., with lyric-without lyric) versions of the same melodic content as stimuli, to study their corresponding bio-signal (EEG) attributes. DFA technique was employed to calculate and compare the Hurst Exponent values for all of the recorded auditory signals as well as the EEG responses. This is a pilot study in the context of Indian music which endeavours to analyze the contribution of lyrics in songs of different genre as well as different emotional content in both acoustic and neuro-cognitive domain.