As I just said in a different thread, I'm transcribing an English text into J.R.R. Tolkien's Tengwar symbols and have decided to go the phonological route. There is always the choice of transcribing orthographically (letter by letter) or phonologically (sound by sound).

To avoid making mistakes, I referred to the pronunciations given in the Oxford Advanced Learner's Dictionary.
I am not a native English speaker, but at Grammar school I was always among the best students while having well-reputated teachers.

So, when looking up the words now, I was well surprised in how many cases the "official" pronunciation differed from they way I pronounced all these words throughout my life till today. In the following lines, I'll list the word, followed by my Dictionary's pronunciation, followed by the way I would have pronounced it.
I'd like to mention that I am looking for a pronunciation in a situation when reading out the words in a slow, celebratory, poetic way.

written word
Dictionary
my pronunciation
melody /ˈmelədɪ/
/ˈmeləʊdɪ/ (when speaking slowly)
to /tə/
/tʊ/ (regardless of the following word)
convey /kənˈveɪ/
/kɔnˈveɪ/
your /jɔ:r/
/jɔr/
until /ənˈtɪl/
/ʌnˈtɪl/
peacefully /pi:sfəlɪ/
/pi:sfʊlɪ/ (when speaking slowly)
heart /hɑ:t/
/hɑ:rt/ ( Iwas so surprised, no /r/ sound??)

Please tell me if my pronunciation would also be right for some of these words. If so, I'd naturally stick to the pronunciation I've grown familiar with.