I asked adam nitti about scales and soloing in the ask a pro section of talkbass.com and he replied with this.
"questions like these are really tough to answer in a single thread, because the scope of improvisation is limitless and is so heavily dependent on context. also, you have to remember that if you have an exclusively scale pattern-dependent or riff-pattern dependent approach to soloing, your ideas are ultimately going to sound contrived and pre-rehearsed, and all of us want to (hopefully) have our own identity that listeners will recognize and be inspired by when they listen to us play.
sorry, keldur16, you may already know all of this but for the benefit of other readers i just felt like the responsible thing to do first would be to make that disclaimer... i just want to make sure everybody understands that scale patterns and shapes are not the pathways to become a great improviser. like i've mentioned in other posts, they are to be used as ear-training exercises so that your repertoire is continually filled with the knowledge of sounds, colors, and moods that you can draw from when playing spontaneously. you don't want to sound like you are simply playing a 'pattern-based-approach' when you solo or play bass lines.
now that i have that out of the way, let me share a handful of the concepts i like to use when improvising.
PENTATONIC IDEAS
believe it or not, i actually still use pentatonics a lot when i improvise, but not in the manner you might guess. it's really cool when you can displace ideas so that they start from different scale degrees in order to create a completely different mood or feel.
for example, over minor 7 chords i will sometimes play ideas that are based on using the minor pentatonic scale from the 2nd scale degree with respect to the chord. a specific application would be to use the D minor pentatonic scale over a C minor 7 chord. this gives you a minor 9/11 tonality that sounds very open and almost 'inquisitive' in nature. you can also play the minor pentatonic scale from the 5th scale degree to get a similar and likewise compatible sound. it still possesses that minor 9/11 quality that sounds really cool over minor 7 chords.
if i want to create more of a cycling dissonance over a minor 7 chord using pentatonics, i will sometimes cycle in and out of the minor pentatonic from the 2nd and the b5th, with respect to the chord. this creates a slightly darker version of the 'inside, outside' manner of phrasing that can create a really neat vibe. of course, you will want to resolve your phrases so that they land ultimately 'inside', either using the inside minor pentatonic idea or something even more resolute like the dorian mode.
another great use of the minor pentatonic scale is to use it starting from the 7th degree of a major 7 chord. for example, you could play a G# minor pentatonic scale over an A major 7 chord. this idea implies a lydian tonality, because the 4th degree of this pentatonic scale ends up being the #4 with respect to the major 7 chord you are playing over.
MELODIC MINOR IDEAS
i use a lot of melodic minor ideas in my playing, as i really love the color and feel of its harmonization. since the harmonization contains several modes that serve well in the context of altered harmony and substitutions, there are a lot of ideas that can be combined and interchanged with standard major scale-based modal ideas.
one of my favorite ideas is to use the minor/major 7 arpeggio from the 5th degree over a dominant 7 chord. for example, improvising using notes from the B minor/major 7 arpeggio over an E7 chord. this is really nothing more than an idea that substitutes E lydian dominant for E mixolydian over the E7 chord, but displacing the starting point and using fewer notes makes it really stand out.
the altered scale is, of course a pretty standard idea that can be substituted for the mixolydian scale over a dominant 7 chord, as well. it has a more sinister and darker feel to it than lydian dominant because it contains all 4 of the altered tones (b9, #9, b5, #5).
i also use the half step diminished scale over 7 chords that are acting as a V...
these are just a handful of some of the ideas i like to use, but of course you can expand on these by starting them from any of their harmonized scale degrees. have fun!"
Its alot to digest but still good info. be blessed.
