When I was at school we used to sing In Our Day of Thanksgiving One Psalm Let Us Offer to the tune Was Lebet, Was Schlebet at our annual Founder's Day service. This tune is commonly used for O Worship The Lord in the tum-tum of holiness, and does not fit as written in most hymnals. To allow use as stated the first note is split (for In our, rather than single for O) and the triplet at the end of the first line (holiness) is changed to a double note (offer). This usage probably dates back at least a hundred years. Sorry about the tum-tum - can't remember where the selzer is!