Do you think it at all possible that ‘the last trump'(Rapture) could be the Tekiah Gedolah or the last trumpet call of the shofar at the feast of Trumpets?
I don’t think so, because I place the 2nd Coming at the time of the Feast of Trumpets. But there is an interesting connection between 1 Thes. 4:16 and Exodus 19:13, and both involve the Trumpet Call of God. In these two cases and only these two it’s the sound of the trumpet that’s important, not the trumpet itself, and in both cases the sound is said to be coming from God. Some theologians say the two trumpets of God recall the two horns of the ram caught in the thicket when Abraham went to sacrifice Isaac. They call the Exodus Trumpet the left one, or First Trump, and say that God will call the Israelites back to the Land in the End Times by blowing the right one, or Last Trump.
If this is the case then the Last Trump will most likely be blown at the close of the Battle of Ezekiel 38-39, placing the Rapture at the time of Ezekiel’s battle, as I believe it to be. But the safest view is that Paul’s use of the phrase last trumpet in 1 Cor. 15:52 is simply to identify the trumpet call that accompanies the Rapture as the last one the Church will hear on Earth.