Shankara invocation

[Cosinuskurve]

The Hare Krishna's start bhajan session with an invocation of their leader. I don't like to do so and therefore I'd like to know whether there is an opening prayer (Shankara invocation?) in Advaita as well.

[wundermonk]

Adi Shankara composed Bhaja Govindam (http://www.youtube.com/watch?v=r4FUQxn4CnY), the opening verses of which are a praise to "Govinda". Some say Shankara is invoking the blessings of Lord Govinda. Some say he is invoking the blessings of his teacher, Govindapada.

Keep in mind that Acharyas of Indian philosophy always begin with an invocation to their teacher, ishtadaivata, etc.