Ionian key = major key = Ιωνιος τρόπος

These names come from the Hellenic mythology.


Ιων, Δωρος.
Ion, Dorus
https://en.m.wikipedia.org/wiki/Dorus_(Deucalionid)


So we have the Ionian mode, Ιωνιος τρόπος which is the standard major 3rd key. Eg
Do Re Mi Fa Sol La Si Do (all white or natural keys).


We also have Dorian mode, Δωριος τρόπος which is a minor 3rd scale which has a change from the standard minor key towards the last notes. Below is the difference between the two.


A minor or A Aeolean, Αιωλιος
A B C D E F G A

A Dorian, A or Λα Δωριος
A B C D E #F G A


So Dorian mode is:
Tone Halftone Tone Tone Tone Halftone Tone


Thanks to Μαρω for letting me know that the names come from Hellenic mythology.


Examples of Dorian mode:
Breathe - Pink Floyd
The Great Gig in the Sky (mostly the vocal part) - Pink Floyd, Claire Tory
To Get Lucky - Duft Punk
Society's Child - Janis Ian