 Of all the strains in the piece, the final D strain is perhaps the most interesting. It is written in B-flat minor. When Joplin used minor keys in the previous sections, he used the relative key of G minor (i.e., relative to the main key of B-flat major). However, in this fourth section, he instead used the parallel key. This strain also features sections where the right hand and left hand play notes in unison, and in which the standard 2 / 4 time left-hand beat is noticeably absent. Most of Joplin's rags end with the last strain, but "Magnetic Rag" ends with a coda. This "smiling little coda" expresses some of the tonalities and rhythms heard throughout the piece.
