Yes, a rhyming poem can indeed follow an "abcb" rhyme scheme, where the first and third lines do not rhyme with each other but rhyme with the fourth line. As for syllables, the choice of syllable count in each line is up to the poet's discretion. Some poems may have a consistent syllable count throughout, while others may vary. Ultimately, the key element in a rhyming poem is the consistent use of specific rhyme patterns, regardless of the syllable count.
