1. I realise there are a few other threads about "blessed" but I want to open a more specific question. 2. I want to know if there is a grammatical difference between the spellings/pronunciation of the word. 3. This is in the context of sacred music. Frequently I come across words where it is unclear whether to give -ed words an extra syllable at the end of the word. 4. This is especially the case in psalms when the rhythm of the words is not given. 5. We take two things for granted, that originally, a long time ago, a lot of words were pronounced with the ed, and that nowadays people generally don't pronounce it, certainly at least in normal speech. 6. What I'm wondering is whether there is actually any grammatical rule as to which is better English, I've heard something about adjectives on the one hand and past participles and such on the other hand, but nothing definitive. 7. Lastly, I would point out that in this music I attempt to be as Orthodox as possible, so using the correct pronunciation from the time when it was first written into English. 8. Examples of such words which are queried: blessed; rebuked; perished; overwhelmed; slaughtered; 9. All quotes/words are taken from Psalms.