 Today  beginning at 12:30 pm here in Washington at the Basilica of the  National Shrine of the Immaculate Conception, a Solemn High Pontifical  Mass in the Extraordinary Form will be celebrated in the Great Upper  Church. For those unfamiliar with all the Church jargon of the previous  sentence let me decode. The “extraordinary Form” of the Mass is the form  of the Mass as it was celebrated prior to 1965 when Liturgical changes  brought about the Mass as we have it today. Prior to these changes the  Mass was celebrated exclusively in Latin with only the homily (and  sometimes the readings) in English or whatever the local language was.  The celebrant also faced in the same direction as the people which some  have wrongfully described as the priest “having his back to the  people.”  To say this is a “Solemn High” Mass means that all the  ceremonial options are observed. There is incense, extra candle bearers,  and many of the prayers and readings  of the liturgy are sung. The  celebrant is also assisted by a deacon and subdeacon. To say this is a  pontifical Mass means that it will be celebrated by a bishop and will  include two extra deacons and an assisting priest. Bishop Edward  Slattery of Tulsa is today’s celebrant.
Today  beginning at 12:30 pm here in Washington at the Basilica of the  National Shrine of the Immaculate Conception, a Solemn High Pontifical  Mass in the Extraordinary Form will be celebrated in the Great Upper  Church. For those unfamiliar with all the Church jargon of the previous  sentence let me decode. The “extraordinary Form” of the Mass is the form  of the Mass as it was celebrated prior to 1965 when Liturgical changes  brought about the Mass as we have it today. Prior to these changes the  Mass was celebrated exclusively in Latin with only the homily (and  sometimes the readings) in English or whatever the local language was.  The celebrant also faced in the same direction as the people which some  have wrongfully described as the priest “having his back to the  people.”  To say this is a “Solemn High” Mass means that all the  ceremonial options are observed. There is incense, extra candle bearers,  and many of the prayers and readings  of the liturgy are sung. The  celebrant is also assisted by a deacon and subdeacon. To say this is a  pontifical Mass means that it will be celebrated by a bishop and will  include two extra deacons and an assisting priest. Bishop Edward  Slattery of Tulsa is today’s celebrant. For those who are unfamiliar or unappreciative with the splendor of  the Latin Liturgy in this form soem questions often arise. 
1. Why pray in Latin or any language unfamiliar to the language of the people who attend?  
Simply  put, praying in Latin is to pray in what has been a sacred language for  the Church. It is a common feature of cultures down through human  history that they often prayed in a language other than the language of  the home and streets. To pray liturgically is to enter heaven, a world  apart from the every day world. To use another and more ancient language  is a common way many cultures have underscored this. 
At  the time of Jesus, the synagogue services and the Temple liturgy used  ancient Hebrew. Jesus and his contemporaries did not speak Hebrew at  home or in the streets any longer. They spoke Aramaic. But when they  prayed they instinctively used the ancient prayers which were Hebrew. 
In  the early Church it appears that the earliest years saw the use of the  Greek language for the Liturgy. It seems to have been used even though  many people spoke Latin throughout the empire. But many did not think  Latin was suited for the Liturgy which required a more elevated language  than what most people spoke. By the 5th Century however Latin came to  be introduced in the Western Empire as it became an older and more  venerable language to them. Eventually Latin wholly replaced Greek in  the liturgy of the Church in the Western empire (except a few  remnants such as the Kyrie). It remained the language of worship until  about 1965 when the local languages were allowed. However,  it was not the intent of the Church that Latin should wholly disappear  as it has largely done. Latin remains for the Church the official  language of her worship. 
So,  why pray in Latin? Why not? It is for us a sacred language of worship  and there is an instinct in human culture that liturgy is  world apart  where we enter heaven. It is not wrong to pray in the local language  but, truth be told, it is not the usual practice in human history.   
 2. Why does the celebrant face away, or “have his back to us?” 
It  is really a wrongful description to say the celebrant has his back to  us. What is really happening is that the celebrant and the people are  all facing the same direction. They are looking toward God. On the  center of every older altar was a crucifix. The priest faced it to say  Mass and all the people faced it with him. He and they are turned toward  the Lord. 
In  the ancient Church, they not only faced the cross, they also faced to  the east to pray. An ancient text called the Didiscalia written about  250 AD says,  Now, you ought to face to east to pray for, as you  know, scripture has it, Give praise to God who ascends above the highest  heavens to the east . In later centuries it was not always  possible to orient the Church so that everyone could face east. But the  Crucifix above the altar represented the east and the Lord. Hence  everyone  faced the Lord to pray. 
The  idea of facing each other to pray is wholly modern and was never known  in the Church prior to 1965.  Hence the answer is that the celebrant is  facing the Lord to pray and so are we. 
3. Why is so much of the Mass whispered quietly? 
Not everything is whispered but the much of the Eucharistic prayer is. Historically  the whispered Eucharistic prayer (or Canon) developed in monastic  settings where it was not uncommon for more than one liturgy to be  celebrated at the same time at various side altars. In those days  priests did not concelebrate masses as they do frequently today. Each  priest had to celebrate his own mass. In monasteries where numerous  priest might be in residence, numerous liturgies might be celebrated at  similar times. In order not to interrupt each other, the priests  conducted these liturgies with a server quietly. This practice continued  into modern times. 
Over  time this monastic silence came to be regarded as a sacred silence. The  whispering of the prayers was considered a sign of the sacredness of  the words which “should not” be loudly proclaimed. (There are other more  complicated theological trends that swept the liturgy too complicated  to go into here that also influenced the move to a more silent liturgy)  At any rate, the practice of a sacred silence came to be the norm  eventually even in parish churches. Hence the hushed tones were not an  attempt to ignore the faithful who attended or make their participation  difficult but it was associated with a holy silence. People knelt,  praying as the priest prayed on their behalf. 
In  the past century as literacy increased among the lay faithful it became  more common to provide them with books that contained the texts of the  liturgy and those who could read were encouraged to follow along  closely. Through the 1940s and 50s these books (called “missals”) became  quite common among the laity. By the 1950s there were also some  experiments with allowing the priest to have a microphone or to raise  the level of his voice so the faithful could follow more easily. These  “dialogue Masses” were more popular in some place than others. Sacred  silence was still valued by many and adjusting to a different experience  was not always embraced with the same fervor, it varied from place to  place. 
Today,  with the return in some places to the celebration of the Old Latin Mass  (called officially the “Extraordinary Form”) this sacred silence is  once again in evidence. For those who are not used to it, it seems  puzzling. But hopefully some of this history helps us understand it.  Once again we are faced with the dilemma of how loudly the priest should  pray the Canon (Eucharistic Prayer) at such Masses. There are different  opinions but a fairly wide consensus that the prayer should be  generally said in a very subdued voice.
DE:http://blog.adw.org/2010/04/why-pray-in-latin/

 inundado por um mistério de luz que é Deus   e N´Ele vi e ouvi -A ponta da lança como chama que se desprende, toca o eixo da terra, – Ela estremece: montanhas, cidades, vilas e aldeias com os seus moradores são sepultados. - O mar, os rios e as nuvens saem dos seus limites, transbordam, inundam e arrastam consigo num redemoinho, moradias e gente em número que não se pode contar , é a purificação do mundo pelo pecado em que se mergulha. - O ódio, a ambição provocam a guerra destruidora!  - Depois senti no palpitar acelerado do coração e no meu espírito o eco duma voz suave que dizia: – No tempo, uma só Fé, um só Batismo, uma só Igreja, Santa, Católica, Apostólica: - Na eternidade, o Céu!
inundado por um mistério de luz que é Deus   e N´Ele vi e ouvi -A ponta da lança como chama que se desprende, toca o eixo da terra, – Ela estremece: montanhas, cidades, vilas e aldeias com os seus moradores são sepultados. - O mar, os rios e as nuvens saem dos seus limites, transbordam, inundam e arrastam consigo num redemoinho, moradias e gente em número que não se pode contar , é a purificação do mundo pelo pecado em que se mergulha. - O ódio, a ambição provocam a guerra destruidora!  - Depois senti no palpitar acelerado do coração e no meu espírito o eco duma voz suave que dizia: – No tempo, uma só Fé, um só Batismo, uma só Igreja, Santa, Católica, Apostólica: - Na eternidade, o Céu!