Plagiarism?

So I had this idea concerning poetry or song lyrics or both since by and large the two are interchangable. The question here is whether or not this can be considered plagiarism although I'll get to that in a minute. Unless you are really good at songwriting/poetry or just don't care there is little in the way of new ideas, new phrases and things of that sort. But what if you took lines from existing songs and poems, many of them, and combined them to form one completely new work. Albeit you'd have problems getting meters to match up, but it could be done with some patience. But could it be considered plagiarism? Personally I don't think so, because you are creating something completely new. The trick, I think, is including lines people know so they can catch on to your deceit.

Another idea along the same lines struck me this past weekend as well. You know how in Wheel of Fortune they have Before & After puzzles? What if you wrote something like that, perhaps not every word, but subjects and titles and things like that. The one that stuck in my head for whatever reason was Silver Bells Palsy.