This was a very tantalizingly challenging rhyme scheme within a rhyme scheme. Last word on line 1 and first word on line 2 must rhyme, same pattern in line 3 and 4, while u continue with an a/b, a/b rhyme scheme for the remainder as the poem compresses! WHY? To hone the craft I suppose hahaha I forget the madman who devised it? Longfellow?