prayers include the Lord's Prayer (Our Father, Pater Noster), the Hail Mary (Ave Maria, Angelical salutation), the Glory Be (Gloria Patri, Minor Doxology), and the Apostles' Creed (Symbolum Apostolorum). Catholics consider vocal prayer an essential element of the Christian life. Vocal prayer can be as simple and uplifting as "Thank you, God, for this beautiful morning", or as formal as a Mass celebrating a very special occasion. When two or more people gather together to pray, their prayer is called communal prayer. Examples of communal prayer are the rosary, devotional prayers including novenas and litanies, classroom prayers, and, most importantly, the Holy Mass. Chanted prayer Ambrose introduced in Milan antiphonal singing of the psalms "after the manner of the East". Mental prayer Mental prayer was defined by John A. Hardon in his Modern Catholic Dictionary as a form of prayer in which the sentiments expressed are one's own and not those of another person. Mental prayer is a form of prayer whereby one loves God through dialogue with him, meditating on his words, and contemplating him. It is a time of silence focused on God and one's relationship with him. It is distinguished from vocal prayers which use set prayers, although mental prayer can proceed by using vocal prayers in order to improve dialogue with God. Mental prayer can be divided into meditation, or active mental prayer; and contemplation, passive mental prayer. Meditation Meditation is a form of reflective prayer which engages thought, imagination, emotion, and desire. There are as many methods of meditation as there are spiritual masters. Ordinary or active mental prayer consists of two operations; one belongs to the thinking faculty which applies the imagination, memory, and understanding to consider some truth or mystery. The other operation is dependent on the will and compels one to love, desire, and ask for the good proposed by the mind, and make resolutions to arrive at it. According to Teresa of Ávila, the soul in this stage is like a gardener, who, with much labour, draws the water up from the depths of the well to water his plants and flowers. Contemplation Contemplative prayer is a silent attentiveness which looks at God by contemplating and adoring his attributes. Teresa describes contemplative prayer [oración mental] as "...nothing else than a close sharing between friends; it means taking time frequently to be alone with him who we know loves us". In this