The Ashtanga Yoga Opening Mantra is sung in two variants: in Call-n-Respond mode or in shared mode.
In Call-n-Respond mode, the teacher sings the Opening Mantra OMs. The group joins the OM. Afterwards, the teacher sings part of the opening mantra, which the group then sings.
In the common mode, the teacher also sings the opening mantra by singing the OM and the group enters the mantra with the OM. The mantra is then sung together. At AYRF we sing in common mode.