1 Kings 1:40
And all the people came up after him, and the people piped with pipes, and rejoiced with great joy, so that the earth rent with the sound of them. And all the people came up after him, and the people piped with pipes, and rejoiced with great joy, so that the earth rent with the sound of them.
The verse portrays the people coming up after Solomon once he had been anointed and publicly proclaimed king, piping with pipes and rejoicing with great joy so loudly that the earth was rent with the sound and seemed to shake. Though lying on his deathbed, David gave a clear and decisive order that Solomon should ride on David's own mule, be anointed king over Israel and Judah by Zadok and Nathan, be heralded with the trumpet, and sit upon David's throne, and God strengthened David with unexpected vitality to act promptly. That anointing at Gihon and the rejoicing that followed it served as the immediate public notice throughout the kingdom of David's order.
Solomon was thus anointed and proclaimed while David was still alive, and afterward he succeeded David and ruled over all Israel. The promptness of that anointing and celebration blocked Adonijah's rebellion. Any delay would have let the usurper gain the advantage, caused Solomon's supporters to be slain, put the kingdom under a despot who could not rule himself, and filled the land with war and bloodshed.