Michael McBride continues Yale's Freshman Organic Chemistry II with a lecture on NMR spectroscopy, covering why chemical shift and spin-spin splitting arise from different physical causes. He explains how through-space magnetic interactions average to zero during molecular tumbling, and how diamagnetic anisotropy accounts for the unusual chemical shifts seen in acetylene and in aromatic and antiaromatic compounds. The lecture then turns to spin-spin splitting, showing how multiplicity reveals nearby magnetic nuclei and why coupling constant J, measured in Hz rather than fractional units, depends only on molecular structure. McBride works through why J depends on orbital overlap rather than spatial proximity, noting the counterintuitive result that anti conformations give larger coupling than eclipsed ones. The talk is organized in three chapters, moving from anisotropy and aromaticity through splitting multiplicity to the orbital basis of J, and runs about 48 minutes with chalkboard derivations throughout.