It is common knowledge that in western practices, the Ionian mode is the I of the major scale. However, it seems slightly odd that the defining mode of the major scale has an avoid note, (the 4th degree, going from C, it would make F an avoid node.) It gives credit to a theory that prior to modern harmonization practices, the defining major mode might have been the Lydian mode.
The Ionian mode, when imposed on the circle of fifths, doesn't make a complete circle with perfect fifths, the distance between B and F is a tritone
C -p5> G -p5> D -p5> A -p5> E -p5> B -dim5> F
When imposing the Lydian mode over the circle, we are able to make an entire rotation around with perfect 5ths
F -p5> C -p5> G -p5> D -p5> A -p5> E -p5> B
Since the circle of fifths is such a dominating force in western harmony, used in everything from chord progressions (I, vi, ii, V, I, a common jazz and classical chord progression, is a trip around the circle of fifths.)to key signature construction, it does pose an interesting point. Why is it that the Ionian Mode is the defining mode of the Major Scale?
The answer might lie in harmonies. The V chord of the major scale, (V7, V dominant 7 or V Major minor 7, however you refer to it) creates dominant pull to the I chord (I major 7). The IV chord (IV major 7, or in jazz, IV Major 7 #11) has no such dominant motion with out the use of secondary dominants, which are not modal. So, one could make the argument that the Ionian mode rose to power in light of the harmonic possibilities.
Chord Scale analysis of F Lydian .
In F Lydian, all notes are available for chord construction, Just Be sure to avoid inadvertent flat ninths
G (Major Ninth or Natural Ninth)
A (Major Third)
B (Sharp Eleventh or Augmented Eleventh)
C (Perfect Fifth)
D (Major Six (in a F Maj 6 chord, more on that later.)Major Thirteenth or Natural Thirteenth
E (Major Seventh)
Flat Nine possibilities
To avoid flat nines, which can really make your voicing sound icky, be sure to voice the sharp eleven higher then the fifth and the major seven should not be below a root. Unless, for some odd reason, you like the sound of a flat nine, if used right, they can really add a lot of dissonances to otherwise pedestrian chord changes, just be careful. Also, if there is a root is in the melody, consider using a Major Six chord.
4/27/04 Tables didn't work well, so had to edit. Also misspelled dominant.
4/29/04 added chord scale anaylsis