One of the fascinating and unique aspects of Hindustani music is the allotment of definite times of the day/night and seasons for rendering specific raagas. Each raaga is supposed to be in harmony with particular human and natural moods and no North Indian musician would dare to render it out of its temporal context. This system attempts to invest both human moods and those of nature with mutuality, reciprocity, through the agency of music. One has no exact idea when or how this psychological association between musical pitches and nature`s moods began. One can only venture a few guesses.

In ancient times, music was inextricably bound to worship, rituals and prayers. Specific hours of the day and night were fixed for performing these rites; the music associated with these rites also came to be associated with a certain yama or cycle of time. During the course of time, these fragile associations became rigid rules. In more organic societies, there existed a vital relationship between human activities and temporal/seasonal sequences, which may explain the association of certain musical notes and tonalities with temporal or seasonal contexts. One knows from experience that different diurnal and nocturnal rhythms affects one`s moods and emotions in different ways. Perhaps, it was one on the basis of the temporal connections noticed between human emotions and moods and times of the day that certain swara clusters were assigned different temporal slots of the day and night. The intent that motivated this classification may have been suggestive rather than prescriptive. Yet, it is difficult to state a categorical, rational and scientific basis for this association.

If examined from a psychological point of view, one would have to reckon with the fact that there exists a subtle relationship between swaras and states of mind. A branch of physics called psychoacoustics informs that music not only has emotional, but also psychological effects. Research is still underway regarding the precise effect of certain pitch registers on the psyche. In fact, the many newly founded institutions, which deem that music possesses immense therapeutic value, through empirical practice, found their arguments on the expressive significance and the healing potential of swaras. They hold that listening to the right kind of raagas can cure physical and psychic illnesses and disorders and generate a sense of well-being. The spiritually initiated and realized persistently speak of the relationship between subtler dimensions of sound and their effect on the deeper levels of the psyche. Mantras, prayer cycles and chants derive their value and potency from the principle of NaadaBrahma, or the awareness that the purest dimensions of sound lead to the highest consciousness. This is only to suggest that the music-time theory founded centuries back in India is not entirely devoid of rational content.

Numerous Karnatic singers and musicologists agree, at least in theory, that raagas rendered during their allotted hour take on a special character; yet they refuse to be curbed by such restraints. Kalyani (Yaman) and Hindolam (Malkauns) could easily figure in a Karnatic morning concert as Mayamalavagowla (Bhairav) or Bhoopalam (Vibhas) in a late evening one.