Chanting is a powerful and delightful practice. It resonates in the instruments of our body, breath and mind, to purify our consciousness and place us in communion with more subtle, higher levels of awareness.
Chanting, sounding with the mouth, the breath, the voice, the mind, creates a vibration that can impact our consciousness, our brain chemistry. It impacts our psychology to have a mantra, a prayer, an invocation, ever on our lips.
Chanting has several variations with differing purposes and effects.
Japa repetition is repetition of mantra without chanting or singing. Just a straight repetition. Japa is often recommended for repeating the Names as a method of meditation.
Chanting then adds a melodic intonation and perhaps some accompaniment from a simple shruti drone to a harmonium or other instrumentation. It may be a simple solo chant or develop into full kirtan with a more energetic and even ecstatic quality.
Chants also vary from mantras to a chosen deity giving homage and chanting the Name, to shastras or sutras, the sacred texts of imparted wisdom, to stories of the deities and other hymns.
Yoga Sutra of Patanjali
Patanjali Asthanga Invocation