1 Chronicles 15:29
And it came to pass, as the ark of the covenant of the LORD came to the city of David, that Michal the daughter of Saul looking out at a window saw king David dancing and playing: and she despised him in her heart. And it came to pass, as the ark of the covenant of the LORD came to the city of David, that Michal the daughter of Saul looking out at a window saw king David dancing and playing: and she despised him in her heart.
The verse records the moment when the ark of the covenant came to the city of David in David's joyful bringing of it from the house of Obed-edom to Jerusalem. At that moment Michal the daughter of Saul, looking out at a window, saw King David dancing and playing. That bringing was David's corrected attempt after the first failure. In the correction the ark was to be carried by the priests and Levites as God had ordained.
David's dancing was to praise the Lord and to the glory of God in a way pleasing to Him. It was not for his own amusement or for public entertainment. It was not with the world's unseemly forms and trashy music. Michal despised David in her heart because she was worldly-minded and was disgusted by a dance that truly praised God. A dance that praises God in this way does not gratify the flesh, please the world, or please the adversary.