Jim Writes in Defence of the Rhymed Couplet
Any poem is held together by its 'unities'. These are usually features of its form often recurring regularly if a stanza construction is used. Content can at times be considered a unity, particularly where it is repeated. See below. In free verse the unity may even be disunity, though not necessarily so.
One type of unity is the poem's rhyme scheme if it has one. For example, the fourteen lines of a Shakespearian sonnet are schemed ababcdcdefefgg with the additional unity requirement of 10 syllables per line. Hired Heart is a song lyric in rhyming couplet form over 6 x 4 line stanzas schemed aabb. One interesting feature is that there is genuine bb in every stanza, an exact repetion of 'pain' rhymed with 'again'. When it is sung, the last line acts as a refrain and is unchanged except in the last stanza. So both this repetition and the recurrence of the word 'pain' are additional 'unities' in this piece. The recurrence of the opening phrase of each stanza: 'So hard to...' is similarly one of the unities, as is the regular scansion throughout. Rhyming couplets lend themselves to certain musical patterns and that scheme is frequently used by lyricists.
A glance at the analysis of poetic devices used in 'Hired Heart' will show that a considerable degree of crafting has gone into this work that might at first sight appear as a banal song of lost love. Try comparing it with Elvis Presley's hit 'Heartbreak Hotel'. The instances of alliteration, internal and crossed rhyme etc. in 'Hired heart' are not in part of the 'unities' of the piece as they appear somewhat randomly throughout but they do enhance the poetic feel somewhat.
The more unities, the tighter the construction and the more difficult to get different ideas across without appearing forced. Another unity here is a unity of content. Each of the six senses is given a stanza. In order: taste, smell, sight, hearing, touch and finally that mysterious sixth sense. There is no overlapping of one sense into a stanza concerned with another.
Working in rhyming couplets is no easier or harder than working with any regular recurring rhyme scheme and the challenge is to make something of it, rather than run away from it and play tennis with the net lowered!