For what purpose is this sacred music performed?

(John Angell James, 1835)  LISTEN to Audio!  Download AudioWith what sentiments may it be supposed that the Son of God beholds the scenes of His suffering life, sin-atoning death, and final appearance in judgment—blended with all the hilarity of a musical festival, and sung by graceless men and women, for the entertainment of the multitude!

Let those whose spiritual vision is not quite obscured by their musical taste, compare the scenes of when "Handel's Messiah" is being performed—and those of the house of God when the Lord's supper is celebrated; and remembering that the subject is the same in both—let them ask if both can be right?

Is the cross on which the Savior loved and died rightly appropriated, when it is used for the purposes of amusement, gaiety and fashionable vanity?

The subject of the Messiah, the Lord Jesus, as revealed in the Holy Scriptures, is given:
  for the purpose of bringing men to repentance, faith and salvation;
  to be the great means, through faith, of overcoming the world with all of its lusts of the flesh, lusts of the eye, and the pride of life;
  to give a death blow to the love of the world in the heart of man;
  and to subjugate the senses and the imagination to unseen and eternal realities.

While in "Handel's Messiah" the cross of Christ, instead of crucifying us to the world, and the world to us—is employed as an amusement to add new attractions to earth, and to yield new gratifications to sense; and thus to make man more effectually the captive of that world, of which he should seek by faith to be the conqueror.

For what purpose is this "sacred music" performed?

It is for amusement! Purely for amusement! Is it then, done for the glory of God—to convert the most solemn and sacred topics of divine truth, into a source of public entertainment? No! It is done to draw people together to hear the sufferings of the Lord Jesus set forth for much the same purpose as they are called to be entertained by a dramatic representation of the sorrows of Hamlet or Romeo!
 

Revelation 5:12-13.
In a loud voice they sang: "Worthy is the Lamb, who was slain, to receive power and wealth and wisdom and strength and honor and glory and praise!"  

Then I heard every creature in heaven and on earth and under the earth and on the sea, and all that is in them, singing: "To Him who sits on the throne and to the Lamb be praise and honor and glory and power, for ever and ever!"

N.B. You may want to read James' full article, "Oratorios", from which the above is excerpted.