This is from my reply to today’s daily post challenge. Some of the references are to others’ comments
Heartbeats are nice and fluffy, but really it has more to do with the natural stress patterns in English. Latin and Greek meter are quite different, and orators were expected to use specific meter in their speeches, and it wasn’t iambic.
It only sounds forced if you don’t know what you are doing (see this awful thing for an excellent example of ‘sounding forced’).
Self deprecation aside, the point of using meter is that it easy to get it right in a particular language but have it sound terrible, and a challenge to make it sound natural. The art of it is in having self-imposed limitations and still expressing your feelings. I would say that this tension forces the artist to look more deeply into his or her feelings. The choice is not arbitrary, but comes about through the need to be challenged in the context of a particular language, and yet still be successful at that challenge. Paradise Lost by Milton is in (a lot) of iambic pentameter. It sounds very natural, well at least to someone in 17th century England. Convoluted at times, most definitely, but not forced.