The practice of chanting is very important in the Kwan Um School of Zen. The school’s name “Kwan Um” means Perceive Sound. Chanting is usually done in group practice and it is a very powerful meditation tool. When we chant together it is important to sound as one voice, this is possible by chanting at a level in which you can hear your own voice and the voices of those in the room. The rhythm in chanting is lead by an instrument called the Moktak. During chanting it is very important to let go of all thoughts and only perceive the sound of the chanting voices and the moktak. By doing so our minds become clear and we can see our true nature.
The meaning of the chants is actually not important. They originated in India and were composed in Sanskrit. From Sanskrit they were transliterated into Chinese and then Korean. These chants are not an invocation or prayer to a deity. As a matter of fact, any chant or sound is as effective if done wholeheartedly. The purpose of chanting is only to perceive the sound, let go of our thinking and stay in the moment.
Zen Master Seung Sahn explains the reason behind chanting. Click here,