.....addi dappa.....addi dappa...actually it's 'a di da phat', and as I found out and means-
'the phrase "a di da phat" alludes to offering respectful praise to the Buddha, in Vietnamese. Often at Buddhist gatherings, especially during chants, followers of the Buddha chant the phrase during services conducted by a Monk. The elongated phrase, "Nam Mo A Di Da Phat" is, too, an utterance of respect offered to the Enlightened One, Siddharta Gotama Buddha.'
And now we know!!!!!
Actually they're chanting the name of the Buddha amitabha...the Buddha of the western paradise where nice dead people go