It’s a very special guided meditation which focuses on the breath, and the sound and meaning of Om.
Chanting Om at the beginning and/or the end of a yoga class has become somewhat customary in Western yoga, and that’s a good thing. It’s good to know what the Om really means; here’s how it’s explained in the classics of the Buddhist yogic tradition.
Om is composed of three different sounds: ah, oo, and mm. Together these three make Om. The ah sound is explained as referring to enlightened action: reaching out to help others. The oo is explained as enlightened speech: comforting others with our words. And the mm is enlightened thought: the intention to be of service to others.