I believe writers of Scripture have made a distinction when it comes to the use of Oh and O. I see a difference in the way they use these two distinct, in my view, words.

And I do not believe it is OK to interchange the two words. I would go as far as saying I am appalled with the apparent ignorance of some writers in allowing such an oversight to creep into their writings. Don’t they think about what they allow on their pages?

There is a pattern to how the King James translators, scholars of English certainly, but commissioned by God to preserve His Holy Scriptures in the then ‘coming’ world language of English, and so clearly ‘helped’ in doing so to produce an error free, better than Elizabethan English text. What they came up with was God’s English. Their usage of Oh and O is consistent.

Consider this usage:

— “O” is used in front of a name to give the effect of sincerity and solemnity or intensity or just real feeling. e.g. Psalm 71:1 In thee, O LORD, do I put my trust:

– “Oh” is really more of an exclamation that people give when in trouble, despair, excitement, hope, anticipation etc. e.g. Psalm 6:4 …oh save me … 

Choice Gleanings Calendar for 14 October 2012 has this text:
I will extol thee, Oh Lord. Psalm 30:1

I would be interested in seeing the Bible that this was copied from. Or is it a ‘typo’? But who doesn’t copy verses these days by doing a copy and paste?

In all fairness, I have seen this type of substandard attention to detail before. I well remember a so-called ‘Christian’ school that had the following verse on its letterheads and promotional pages:

Teach me Thy way, Oh Lord.

Nobody raised an eyebrow for ten years until it was pointed out by some alert teacher, I think, and they changed it. 

I will extol thee, Oh Lord should read I will extol thee, O Lord.

Teach me Thy way, Oh Lord should read I Teach me Thy way, O Lord.