Harmonic analysis of the jazz standard “What Is This Thing Called Love?” by Cole Porter.

What Is This Thing Called Love was composed by Cole Porter in 1929. The song follows a 32 bar AABA form and is originally in the key of C major. This is an analysis of the harmony in What is This Thing Called Love and an explanation of the concepts used in the analysis. The image above shows my full analysis, which I will explore in more detail below. You can refer to the conventions page to explore the analytic concepts used or get the PDF for free.


Although What Is This Thing Called Love is mostly comprised of relatively simple sequences of ii — V — I cadences, Porter uses borrowed chords extensively to create an ambiguous harmonic backdrop for his singable melody. The original key is C major, but chords are borrowed from the parallel C minor throughout. There are some unexpected resolutions throughout, notably at the end of section A where a minor ii — V resolves to a major I. The harmonic characteristics of this tune make it great for improvisation and create an interesting analysis. 

Section A

The tune opens with ii — V of IV. However, this is a minor ii-7(b5) — V7(b9) that resolves to iv-7. The minor iv can be thought of as a borrowed chord from the parallel minor. This is followed by another minor ii-7(b5) — V7 that resolves somewhat unexpectedly to the I major. 

Section B

Section B begins with a brief modulation into Bb, the bVII of C. It begins with a C minor to F7 cadence, which I wrote as ii — V/ bVII. The ii — V resolves to the bVII for two bars before a move down a step to the bVI. A ii-7(b5) — V7(b9) in the original key leads back to the final repeat of section A.