Harmonic analysis of the jazz standard “Summertime” by George Gershwin.
Summertime was composed by George Gershwin in 1934 for the opera Porgy and Bess. The song has a simple 16 bar form and was originally in A minor. This is an analysis of the harmony in Summertime and an explanation of concepts used in the analysis. The image above shows the full analysis which will be further explored below. You can refer to the conventions page to explore the analytic concepts used or get the PDF for free.
Although this song seems simple harmonically, it is a beautiful composition and is an amazing vehicle for improvisation. It is in a minor key and the first several measures alternate between the i-7 and V7 in a perfect cadence. The end of measure 4 goes to the V7/iv tonicizing the iv before going to iv-7. The next chord is the VI7,which could be thought of as a modal interchange chord from A Locrian. This is followed by a ii-7(b5), V7, i-7 in the key before repeating the V7, i-7 cadence. The last line has a secondary dominant V7/VII before a VII7, IIIΔ7, i-7. This is followed by a ii-7(b5), V7, i-7 before the V7, i-7 turnaround leading back to the top.