Guitar Forums

Go Back   Guitar Forums > Skills > Theory

Thread Tools Display Modes
Old 10-16-2017, 12:58 PM   #1
Senior Member
Join Date: Jun 2015
Posts: 316
zanshin777 Just getting started
Default Why half steps in the scales are where dissonance happens? (Pinpointed Link)

Key : C Major

He says

F (4) wants to resolve to E (3) and B (7) wants to resolve to C (8). Because of Half-Steps.

and he says those half steps are where dissonances happen.

How and why?
zanshin777 is offline   Reply With Quote
Old 10-16-2017, 03:21 PM   #2
Senior Member
Join Date: Mar 2016
Posts: 145
JonR Just getting started

Half-steps have the strongest "tendencies", but which way they move depends on context.

In the key of C major, normally F will tend to E, and B to C. But if the chord is F or Dm, then E will resolve up to F. Likewise if the chord is G or Em, then a C will resolve to B.

I.e., it's about chord tones. Dissonance is always in relation to a current chord, and the resolution involves a move to the nearest chord tone (up or down).

An implied harmony - with no actual chords - may be enough. So, you could have a melody using the C major scale, which ends on C. Add an F above that C and it will "want" to resolve down to E.
That is, we want it to resolve, because the melody has told us C is the tonic, while F is the acoustic root of a C-F interval (we perceive that subconsciously). That means F is fighting the established tonal centre. Moving to E creates a consonant major 3rd in which C is the root. C wins, as it were. F could also move up to G (to create a consonant C-G 5th), but E is closer. We also psychologically expect the resolution of tension to be a "descent" of some kind, a "fall" - a relaxation. ("Cadence" derives from the Latin "to fall".)

The additional factor is when F and B occur together, forming a dissonant tritone (as happens in the G7 chord). That makes resolution more urgent. In C major, the interval resolves by the notes moving in opposite directions: F-B opens out to a E-C minor 6th (C is still acoustic root), while B-F closes in to a C-E major 3rd.

But F-B on its own is an ambiguous interval. It could be F-Cb (tritone in key of Gb major), in which case it will resolve to Gb-Bb. This is the basis of the jazz tritone sub.
JonR is offline   Reply With Quote
Old 10-20-2017, 02:25 PM   #3
Senior Member
Join Date: Jun 2015
Posts: 316
zanshin777 Just getting started

Thank you very much for your detailed answer JonR.
zanshin777 is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT. The time now is 07:15 AM.

Powered by vBulletin® Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Guitar Competition | Piano Lessons