Trumpets That Clarify Timing?

Do the trumpets of the Bible teach us anything significant?

1 Thessalonians 4:16 For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trumpet (Greek 4536 - Salpinx) of God: and the dead in Christ shall rise first:


1 Corinthians 15:51-52 Behold, I show you a mystery; We shall not all sleep, but we shall all be changed, (52) In a moment, in the twinkling of an eye, at the...last... trumpet: (Greek 4536 - Salpinx) for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.


Revelation 8:2 And I saw the seven angels which stood before God; and to them were given seven trumpets. (Greek 4536 - Salpinx)
Rev 8:7 The first angel sounded, (or in other words blew his trumpet) and there followed hail and fire mingled with blood, and they were cast upon the earth: and the third part of trees was burnt up, and all green grass was burnt up.
Rev 11:15 And the seventh angel sounded; (or in other word blew his trumpet) and there were great voices in heaven, saying, The kingdoms of this world are become the kingdoms of our Lord, and of his Christ; and he shall reign forever and ever.

Do these 7 trumpets in Revelation occur during the tribulation period? What does God mean when He tells us that Jesus will come at the last trumpet? If the trumpets of Revelation precede the trumpet of Christ's return then perhaps we wont be changed until after the tribulation???