Tension & Release

If you find when you solo over certain chords using scales other than the major and minor pentatonic or blues scales, that your soloing is disjointed, lacks continuity and coherence then read on.

One of the most important aspects of good improvisation is the use of tension and release.

The first place to start is getting to know which notes in a scale are the tension and release notes.

Lets look at the C major scale.

C Release Note
If you play the note C over a C major chord you can hear that it is a safe note, maybe even a bit dull, it's not considered a tension note.
D Tension Note
The 2nd has a leaning towards the 1st.
E Release Note
The 3rd note is deemed to be consonant.
F Tension Note
The 4th note creates some tension and has a tendency to want to resolve to the 3rd.
G Release Note
The 5th is deemed to be consonant.
A Release Note
The 6th is deemed to be consonant.
B Tension Note
The 7th is a tension note with an impulse towards the 8th.

With that knowledge you can start to create tension and release in your solos, this takes time, but I suggest, if you are starting out, avoid hanging on the 4th and 7th notes for too long when using the major scale to improvise over a major chord, get used to moving the 4th to the 3rd, 7th to the octave.

Remember!

If you play only tension notes you will agitate the listener, if you only play release notes you will send your listeners to sleep! This should be a consideration next time you go for a solo.

Tension and release is applicable to chords also; you will find more information on this in the major II V I progression