Is there a difference between Ionian mode and the major scale? C Ionian mode and the C major scale are the same collection of pitches. Does that mean that they are the same thing? There is a lot of confusion about this. Classic FM says that C Ionian and C major are interchangeable. This Stack Exchange thread says they aren’t, with some useful historical context. The difference really comes down to pitch centrality. The C major scale has a strong sense of being centered around the note C, and it implies the whole complex system of tension and resolution that you learn about in music theory class. By contrast, C Ionian mode doesn’t so much “function” as it drifts around without really progressing.
It’s hard to find examples of Ionian! There are plenty of pop songs based on the white keys of the piano whose key centers are ambiguous between C major and A minor, but it’s hard to find a piece of major-scale music that just floats around. The closest thing I can think of is Björk’s beautiful tune “The Anchor Song”, with its delightfully angular saxophone arrangement that she wrote with Oliver Lake.
Björk has talked a bit about writing “The Anchor Song”, but only about the lyrics, not the music. She has conservatory training and is deliberate about all of her note choices, so I’m sure she constructed this tune with intention, but I don’t know what that intention was. I figured the tune out by ear a while ago, and came up with a guitar arrangement that I’m proud of, but I didn’t try to write it out. Recently I tried to warp the song out in Ableton, and I discovered that I could not suss the meter out at all.