A nice thread you resurrected, Andreea.

We should not confuse irregularity (or breech of convention) with imperfection; the former, as has been pointed out by Joe and others, is a mark of true art, and can well be "perfect" in that sense.

There are some good reasons for deliberate blunders. For example, subordinates may fear the very earthly jealousy of their human masters. As for God in monotheistic religions, in my opinion it amounts to a blasphemous boast to say "if I had not blundered deliberately, I would be as perfect as God!"

In folk revival music - to justify this thread's upline status - deliberate breeches of poetic criteria are frequently committed in order to suggest that the authors are "ordinary folks", or even that the song is old and "genuine". A number of apparently "trad." songs have thus been spread and become popular, whereupon the author jumped from behind a bush and collected royalties.

Needless to say that such practices are not likely to earn you a good reputation. Songwriters should by all means avoid stale regularity, but should account to themselves whatever they do. To my taste, "imperfect rhymes" are rarely a good idea.

Among all the perils for humankind, perfection is the most unrealistic one, except for perfect destruction.