GS4 (1235) and GS4 (1345) in the tonic of a major key are similar but with a subtle difference. Of course when used in chords other than major and the GS are comprised of scale-of-moment tones, this comparison changes. If the two GS are stated in major, then the comparison holds.
The differences between GS (1235) and GS (1345) in major.
First, let's examine the things that are the same in each. They both have a root and perfect 5th and a major 3rd. The differences are important and occur in a 4th note apart from 135. GS 1235 has the 2nd degree which is neutral and has an effect of thickening the overall sound of GS 1235. Where as GS 1345 has the 4th degree which is a tendency tone that is a half step above the 3rd and has a tendency to fall to that 3rd. With GS 1345 when the tendency is not exercised in a melodic or chordal sense it creates sounds with a little more 'edge' and is has a possible dissonance that is attenuated somewhat in a chord sound. Both are useful and are often used together in a string of sounds but there is a definite difference that can be applied.
These two GS (I've taken to calling them GSA [GS1235] and GSB [GS1345]), originate from the 'major' pentatonic scale. GSA on the root of the major and GSB on the 6th of the major as in a relative minor of C major. As a result of this, GSB has a minor 3rd and has a sound that is sounding quite a bit like its major partner GSA. This does affect the approach to doing scale tone GS. For example in C major, the GS (A or B) would be (could be) dictated whether or not the third is major or minor. See Figure 1.
GSA and GSB originate from the major pentatonic scale:
GSA and GSB found within a major scale.
In Figure 2 below, the GSA (1235) and GSB (1345) in a major scale are outlined.
GSB (1345) as major.
This 2nd GS I'm calling Generic Shape B (GSB) is, as stated above, often associated with minor, but it also serves in today's sounds in major and dominant chords. Not only from the root but also as pluralities or slash/chords to produce this edgy but masked sound that is (can be) virtually found in all chord qualities to some degree (This is also true of GSA ). Chord qualities that can support GSB (and GSA and so on) will be outlined in a later blog but meanwhile here are a couple of examples just to get this idea across see Figure 5. Figure 4 exemplifies the establishment of new shapes (from the primary GSB) generated through simple inversion/Rotation (R). See Figure 4.
New GSBxR that produce 3 new shapes from the original (total: 4).
Chord qualities from different roots that enable GSA example: C(1235), and below that, chord qualities from different roots that enable GSB example: C(1345).
Here's a summary of GSB (1345) on C with BP1—6 x R1—4 and S1—4... for a total of 96 permutations.