This is Psalm 23 rearranged using all of the words. (Comments below.)
The KJV
KJV in a response format, imagine two groups of singers calling to each other.
KJV- just grouped differently.
The Lord is my shepherd; I shall not want.
2 He maketh me to lie down in green pastures: he leadeth me beside the still waters.
3 He restoreth my soul: he leadeth me in the paths of righteousness for his name’s sake.
4 Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me.
5 Thou preparest a table before me in the presence of mine enemies: thou anointest my head with oil; my cup runneth over.
6 Surely goodness and mercy shall follow me all the days of my life: and I will dwell in the house of the Lord for ever.
The Lord is my shepherd.
I shall not want.
The Lord is my shepherd.
2 He maketh me to lie down in green pastures: * he leadeth me beside the still waters.
The Lord is my shepherd.
3 He restoreth my soul: he leadeth me in the paths of righteousness for his name’s sake. * 4 Yea, though I walk through the valley of the shadow of death.
The Lord is my shepherd.
I will fear no evil: for thou art with me; * thy rod and thy staff they comfort me.
The Lord is my shepherd.
5 Thou preparest a table before me in the presence of mine enemies: * thou anointest my head with oil; my cup runneth over.
The Lord is my shepherd.
6 Surely goodness and mercy shall follow me all the days of my life: * and I will dwell in the house of the Lord for ever.
Each star * could be another repeat of the Lord is my shepherd, that might require changing words.
The Lord is my shepherd.
5 Thou preparest a table before me in the presence of mine enemies: thou anointest my head with oil; my cup runneth over.
I shall not want.
2 He maketh me to lie down in green pastures: he leadeth me beside the still waters.
4 Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me.
3 He restoreth my soul: he leadeth me in the paths of righteousness for his name’s sake.
6 Surely goodness and mercy shall follow me all the days of my life: and I will dwell in the house of the Lord for ever.
David, like Moses and Miriam, composed, played, and sang songs. Some of his songs are identified as to where and when they were written. Following that thought, it was a fun study to place some of his other songs into context. No, I can not prove the circumstances that David composed his songs in.
I think that Psalm 23 was possibly his first song. I can see David watching his sheep and realizing that is how Father God took care of him. Many of David’s psalms carry and advance the lyrics of this song. To further the setting, it may have been written right before or shortly after his anointing by Samuel (16:1-13). Then the supernatural anointing took over and he excelled in his music. I think that David was a young shepherd, like his grandmother Rachel, about twelve years old when God and Samuel changed his life. Personally, I think that David did not go into Saul’s service for several more years, maybe seven or eight. In that time he excelled as a musician and killed his lion and bear. These are the things that brought him into Saul’s service.
To offer a reason for the variations of the words, I will sight Psalms 14 and 53 and how close Psalms 135 and 136 are worded.
Mark's Bible Study 
Love this Psalm! Can easily see the response repeating. Thanks!
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