Perfect 4ths, 027 Trichords, sus2 & sus4 combinations and Pentatonic structures, are all in evidence here.
Aside from the fact that the line itself sounds and works well as an "in-out-in" option over a ii-V7-I cadence, it's worth checking out how the aforementioned elements combine and overlap.
2 semitones up would be D and 7 (from C) would be G.
027s are perhaps more commonly known as suspended, or "sus" chords. Again, C-D-G would be called Csus2, or when inverted (G-C-D), with G as the root, could be labeled as Gsus4.
An 027 trichord contains the intervals of a Maj 2nd and a Perfect 4th (P4th), or in its first inversion (rotation), 2 consecutive P4ths (D-G-C).
As a kind of "find the faces in the picture" game, can you find the 027s (sus chords) in the melodic line below? C'mon, give it a shot!
Bar #2 - (D#)-F-Bb, F-Bb-C, C-G-D and D-E-A /
Bar #3 - F#-B-C#, C#-G#-Eb, Eb-F-Bb and F-Bb-C
Bar #4 - (C)-G-D and D-E-A.
A parenthesis indicates that note belonging to a previous or subsequent measure.
Looking at the above melodic line from the perspective of Perfect 4ths is revealing as well. Much has been written in these pages about the close relationship between the Pentatonic Scale and P4ths.
Bar #1 contains 4 pairs of P4ths in whole steps. They are all ascending except for the 3rd one (C#-G#). This group of P4ths, in turn, creates overlapping Pentatonic sonorities of A, F# and B Pentatonic, and contain all the notes of each (A-B-C#-E-F# = A Pentatonic, F#-G#-A#-C#-D# = F# Pentatonic, B-C#-D#-F#-G# = B Pentatonic).
In bar #2, colors from Bb, C and F Pentatonic are all available - again as four pairs of P4ths.
F#, G#(Ab) and B Pentatonic are combined and overlap in bar #3, and if we count the G in bar #4, we've got a straight Eb Pentatonic.
The rhythmic contour of this melodic line is reminiscent of the first half of John Coltrane´s Miles' Mode.
Influences!
B. Stern