From Speech to Recital -- A case of phase transition? A non-linear study

A question has been whirling in the musical fraternity for generations. Which comes first? Melody or lyrics? The answer to which is still unknown. It is well established that the lyrics play a very important role in portraying the emotional content of a particular recitation or song. The audience intuitively listens to the lyrics of the song or recitation and tends to get an idea of the mood of the song or recitation. But what would happen if the lyric part is separated from the melody and conveyed to the audience as a separate entity altogether. Would the emotional content of the recitation remain the same or the meaning would change altogether? A recitation is a way of combining the words together so that they have a sense of rhythm and thus an emotional content is imbibed within. In this study we envisaged to answer these questions in a scientific manner taking into consideration five well known Bengali recitations of different poets conveying a variety of moods ranging from joy to sorrow. The clips were recited as well as read by the same person to avoid any perceptual difference arising out of timbre variation. Next, the emotional content from the 5 recitations were standardized with the help of listening test conducted on a pool of 50 participants. The recitations as well as the speech were analyzed with the help of a latest non linear technique called Detrended Fluctuation Analysis that gives a scaling exponent, which is essentially the measure of long range correlations present in the signal. Similar pieces were extracted from the complete signal and analyzed with the help of DFA technique. Our analysis shows that the scaling exponent for all parts of recitation were much higher in general as compared to their counterparts in speech.