This recording follows the Guided Four Tetrads And Four Foundations Meditation recording posted just prior to this posting.  During the talk, Peter reviewed the 16 stanzas/four tetrads of the Anapanasati Sutta, explaining that the first three tetrads focus on the cultivation of samadhi/passadhi (concentration and tranquility), primarily through using the first and second foundations of mindfulness (mindfulness of the breath/body and mindfulness of feelings) to set aside the five hindrances to samadhi/passadhi.  The fourth tetrad involves the cultivation of vipassana, that is, the direct knowledge of impermanence, which, along with samadhi/passadhi, develops dispassion, liberation from craving/clinging and letting go of the misperception of a secure, enduring self.