An INCANTATION is a chant, usually rhythmical, often using repetition, and suggesting a magical connotation.
INITIAL RHYME is another term for alliteration, where the opening consonant sounds in consecutive or closely-placed words are the same, such as blow big bubbles.
The IN MEMORIAM STANZA is associated with Tennyson and his masterpiece In Memoriam AHH, written over a period of seventeen years after the sudden death of his friend Arthur Henry Hallam. It is a quatrain envelope stanza, in which two rhyming lines wrap themselves around a rhyming couplet. This creates a rhyme pattern of: a b b a. Iambic tetrameter is used throughout the poem, as this stanza from a love poem demonstrates.