Kirtan involves using mantra/nada yoga, which is the science and art of using vibratory frequency and sound current to help a person experience mental calmness and a sense of unity with all creation and consciousness. It uses primal sounds to connect the cells of the physical body to the subtle qualities of the mind. In nada yoga, mantras are chanted or repeated mentally and traditionally practiced with a straight spine in a meditative posture.

The word mantra is a Sanskrit word composed of the root man meaning “to think” and tra meaning “instrument to liberate us from bondage.” Thus, the word means “an instrument of thought that can free us from the constraints of our mind.”

Chanting mantras can affect the body in several ways. Repetition of mantras causes vibration in the sphenoid bone and sella turcica of the brain, while at the same time, the tongue stimulates acupuncture meridian points on the roof of the mouth, both actions in turn causing stimulation of the hypothalamus, pituitary, and pineal gland. It has been noted that intoned mantras can stimulate endorphins and neurotransmitters and change brain wave patterns. From a Tantric yoga perspective, as mantras are chanted, energy of the sound current creates a channel of healing energy, which travels through the spinal cord to stimulate the energy centers of the body, the chakras. Thus, through the practice of nada yoga, we can enhance efficient cellular communication, stimulate our immune system, improve our physical health, and calm the mind.

According to Vedanta and Tantric philosophy, consciousness is single, unified, and complete. Consciousness is the intelligent underlying force of the universe and has the inherent desire and the ability to know and experience itself. To become aware, consciousness needs to become differentiated from one into many, so that the many can know the one. The first manifestation of this differentiation is vibration. Human beings experience this vibration in the form of subtle sounds called mantra. This infinite vibration is heard in deep meditation, when the senses and the mind are quieted. Thus, when humans listen for and experience this vibration, they are actually hearing the faint echoes of underlying universal undifferentiated consciousness as it manifests into form.

Because mantras are an expression of a more complete, unified state, they are uniquely linked to an expanded level of consciousness. Mantras help to focus the mind on a single thought and, through consistent practice, they also replace distracting conscious thoughts and disturbing memories from the subconscious. Constant repetition of the mantra and listening to its sound quiet the mind, create inner silence and gradually pulls individual consciousness towards the universal.

In deep meditation ancient practitioners have described hearing subtle sound vibrations. Mantras are actually condensed forms or seeds of that vibration experience. Being a seed, it can be nurtured to grow into the entire experience. These mantras have been passed on through a long line of teachers. It has been recognized that teachers are simply acting as transmitters, first picking up the sounds and then distributing them to receptive students. The mantra itself may be a small word, but being a seed, it has a very powerful effect because of its latent force.[i]

There are several types of mantras. Bija mantras are chosen by meditation teachers based on the personality and life circumstances of their students. Therefore, the mantra can be used not only to help focus concentration but also to help the student with specific difficulties. The teacher selects the mantra similar to a physician prescribing a medication, except in this case the diagnosis and prescription are made on the spiritual level.

The vibration OM can be heard when the mind is calm in deep meditation, reverberating through our minds and the universe around us. OM is the primordial sound of timeless consciousness, vibrating within us from the beginningless past. The sound is approximated when putting your ear up to a seashell, or trying to talk with your lips closed. Almost all religious and spiritual traditions have a close form of this sound in its prayer or meditations. In Jewish meditation, the word for peace is SHALOM and is often used as a mantra in meditation. In  Christianity, prayers end in the word Amen, which approximates the sound of OM. In Hinduism and Buddhism, OM is chanted at the beginning of most prayers and rituals.