Check out this page where the image is given. Here you can select a key and click a chord in order to show the actual pitches of that chord.
For instance, "I/5" in C major is listed as G C E G
. Since G
is both scale-degree 5 and the chordal fifth, it's still unclear what 5 means. But when we see that "V/2" is listed as D G B D
, we realize that these integers refer to scale degrees.
As a friendly PSA, beware of some of the pitches on this chart; their little algorithm has quiteprivileges flats over sharps, so chords are sometimes spelled a bit of trouble determining the "correct" enharmonic pitcheslittle strangely (e. As one exampleg., they list E major as E A♭ B
).