Leon Russell recorded a version that uses this chord progression except for the third line. In this case, seen in Ex. 3, rather than descend from E to Eb to make the C to Cm (IV to IVm) change, as in Elvis’ version, Russell ascends from the root, following the IV with a #IVdim7 (C#dim7). He then puts the 5 in the bass of the I (G/D) and finishes the line with the IVm7 (Em7).
Many versions of “I’m So Lonesome I Could Cry” feature key changes, including later on in Russell’s version, as well as recordings by Jerry Lee Lewis and Roy Orbison. Glen Campbell’s take on the song, seen in Ex. 4, involves two key changes, and he uses a slightly different set of chords in each of the respective keys. In the first 16 measures, shown here in the key of F major, Campbell uses the chord changes on the I chord from Ex. 2 with the maj7 and 6 chord reversed. After two passes through this progression, he ends with a C#7, which is the V chord for the following key, F# major.
In the F# major progression, Campbell follows the IV chord (B) with a bVII (E), which then moves up a tritone to go to the IIIm (A#m7, written here enharmonically as Bbm7) before moving to the VIm (D#m7, or enharmonically Ebm7). Once in the key of G, Campbell sticks to the same set of chords until the ending, where he follows the I–V in the first two measures by modulating keys up one half-step for a V–I in Ab,before resolving and ending the song with a G major.
While most artists favor the waltz-feel of the original version, others, such as Little Richard and Al Green, have changed the feel to a funkier 4/4. Ex. 5 features the chords used in Green’s version, where the chords change every two beats. The first two measures move around the key with a I–IIIm–VIm–V (G–Bm–Em–D) progression, which shifts in the next two measures to I–IIIm–bVII–I (G–Bm–F–G). The second line is the same set of chords used in Ex.2. The ending walks down from the V (D) to the IV (C), IIIm (Bm), and IIm (Am), then moves up to a Eb7 (the V7 of Ab) for one beat, as if it were changing keys, only to resolve back to the original V (D) and then the I (G).
Try these ideas on some other songs or go listen to more versions of “I’m So Lonesome I Could Cry” and see if you can spot the differences. This type of exploration is a terrific way to expand your knowledge of harmony and chord substitution.