Om is an ancient Sanskrit mantra traditionally chanted at the beginning and ending of yoga classes.  When the voices of many blend into one the primordial sound of the universe is created.  The sound is made up of four parts, A-U-M and the silence at the end. 

It represents four states of consciousness.  The waking state is represented by the sound “A” (pronounced like “A” in ahead) and denotes the power of creation.  The sound originates in the back of the throat. 

The dream state is represented by the sound “U” (pronounced like “U” in would) and denotes the power of preservation.  The sound originates in the middle of the mouth.

The deep sleep state is represented by the sound “M” (pronounced like “M” in hum) and denotes the power of destruction.  The sound originates and ends at the lips.

The state of bliss is represented by the silence at the end when the individual self recognizes his or her identity with the supreme.

Om represents the supreme consciousness and all that is sacred in the universe. It cannot be expressed in words.  When we chant Om we take refuge in our own true nature, we feel connected to everything and it reminds us that we are all one.