So, you have become a little tired of simply playing your favorite songs without adding a little of yourself into the mixture? Or perhaps you are simply looking to expand your understanding of these favorite songs by exploring their inner harmonic and tonal fabric?
Whatever your reason for being here, let me be the first to cordially welcome you along this path, where we will be helping you to assess for yourself what scales to use over what chords, providing you with the tools necessary to explore these things for yourself and thus to imbibe them deep within your creative unconscious.

There are several ways you can approach this aspect of improvisatory playing, and thus several different ways to answer what scales to use over what chords. There are, in fact, a near-infinite amount of scales and possible combinations to choose from, which is precisely what makes improvisatory music, like jazz, all the more interesting, as you never quite know what you are going to hear night after night.
Top improvising artists all have their own unique styles, and it is these individual styles that draw people in so much, the building blocks of which are the scalic choices they make.
Soloing by Key
One of these possible options is to solo over a particular key throughout a song. This is by far the easiest method of what scales to use over what chords as the song is essentially treated as one large chord which can be soloed over without much modification on the part of the musician.
Now, while this is not possible for all songs or pieces of music, you will find that for a large majority of popular songs in the rock and pop sphere, this will work a treat, and will modify the way that you see these kinds of music forever.
Selecting the Scale
If your song already has a designated key then you are up, up, and away, for it will already be less of a challenge for you to work out what scales to use over what major chords.
If the key is not provided and you can’t seem to find it anywhere online, then you will have to use your ears and fingers to suss it out, plucking some familiar notes along to the tune while using your ear to see which works best, even making a note of them with actual paper and pencil (!!!) if this will help.
In the rock sphere, many improvisers will use a harmonic minor scale, a minor pentatonic scale, or even a blues scale, despite this not being entirely called for all the time. I can’t count the number of songs I have heard whose entire fabric has been soiled by the wanton addition of a minor leaning scale in place of a major scale.
Perhaps this is just my own partisan preference for the major scale notes and their counterparts over others, but I wish people would use their ears a little more when working on a song in this fashion.
This is not to say that a natural minor scale cannot be used within the context of a major key, nor is it to say that a major scale cannot be used in the context of a minor key! In fact, I would be the first to encourage these kinds of experiments in one’s own musical journey as they can very often lead to important and epiphanic discoveries that are only elicited and truly imbibed when discovered oneself.
Learning about what are relatively minor and relative major keys, for example, certainly taught me a thing or two about tonality at a very crucial point of my development as a musician.
Soloing with the Scale
Now that you have sussed out what scales to use over what chords (or thereabouts), you can theoretically go right on ahead and play any of the notes within the scale over any of the chords, and this should work a treat.
If, however, you do not have much experience with soloing and the like, then the phrases that you use could very easily come to sound quite wooden and uninspired. Cue some apt and timely tips on how to think about the appropriate scale you are using to solo over the chords you have chosen.
Thinking about where the phrase ends in relation to the chords is a useful way to start imagining the impact your notes can have on the overall picture you are attempting to paint.
Some suggest ending the phrase on the root note of the particular chord, which is certainly a useful place to start, though playing the major or minor 7th (if it calls for it) might be an interesting way to anticipate the next chord or to add some tension.
Using one’s ears is vital and will have you excelling far beyond the bounds of any how-to guide, for you will be forming your own stylings and phrases based on what sounds the best to your ears and feels best beneath your fingers.
Some notes will feel better with certain major chords than others, some parts of the fretboard and even some strings will feel better alongside certain chords than others. Thus, paying attention to your own sensory inputs as much as possible will ensure that you are learning and absorbing to the best of your ability.
Soloing by Chord
Soloing as per the key of the chord is all well and good and can often yield some pretty interesting results, but the more adept soloists will at least learn to solo by the chords of a song as opposed to the holistic key.
Chords tend to change rather frequently, and even keys if you are into your jazz or classical music, so attempting to map one’s improvisations alongside these chords is likely to produce more interesting results more frequently, no matter how rapidly or slowly they might be changing.
As with anything, however, I might suggest that balance between key soloing and chord soloing is vital and most tasteful.
Pentatonic Scales
A pentatonic, whether major or minor, is a scale that has five scale degrees instead of seven, hence the name. This makes it perfect for those seeking a more simple and sparse approach to composition and improvising, in which you might add something more of yourself, through expressiveness and the like.
The major pentatonic is the exact same as its major scale counterpart, having had its 4th and 7ths removed, and the same goes for the minor pentatonic, this time with the removal of its 2nd and minor 6th.
It can be hard to go wrong with a pentatonic scale, as they are very spacious and offer the user plenty of room to navigate between plenty of chords while still allowing more opportunities for self-expression within the context of the lesser amount of notes as compared to a more traditional scale.
They also work really well with just about any chords you throw at them, and – owing to their lesser number of scale degrees – allow for more comfortable chord extensions and the like.
The five notes of a pentatonic that can be considered one of their key strengths can also be considered one of their weaknesses, as they are often discarded for being so simple and repetitive as to encourage these very qualities in one’s own improvisations, even despite their simplicity offering plenty of room for the user in question to improvise and economize.
Nevertheless, if you are new to soloing by chords, then the minor pentatonic scale is an apt place to start as there is far less to think about, making the actual switching between chords a whole bunch easier. The key to soloing over chords is to make the transitions between the chord changes as lubricated as possible, and the minor pentatonic scale provides an apposite way into working on this oneself.
Why not try moving through these blues chord changes with some blues licks in your own time?
Minor and Major Scales
Just as you can use a particular major scale and natural minor scale with a particular key, and just as you can use pentatonic scales to move between chords as they come and go, you can combine both these techniques to devastating effect to work on your own conception of what scales to use over what chords.
This will be more difficult and will require at least a little more work than doing so with pentatonic scales, if only for the numerical addition of two more scale degrees to consider at all times. Thus, you should only really seek to tackle these kinds of chord changes with major scales and minor scales once you feel at least somewhat comfortable doing so with the relative pentatonic scale.
The major and minor scales will do you for just about any chords you are likely to come across and can be extended through one’s own will just like the pentatonic scales can, as described above.
The major scale and the melodic minor scale can even be described as modes, for they very much are, being the archetypal major and minor modes respectively.
You may find the major scale is referred to out in the field as an Ionian mode which belies the fact that they are exactly the same, with the Ionian being the first mode of permutations of the major scale (thus unmodified).
The same goes for the melodic minor scale appearing as the Aeolian mode, the sixth permutation of the major scale, using the sixth degree of the root major scale as its own tonic note (turning it into a relative minor of sorts).
Soloing with the Modes
The modes, however, are a whole different ballpark and ought to be treated as such. Even if you have come to be pretty good at soloing over chord changes with the major and natural minor scale, it does not necessarily preclude you from moving straight to using the modes with ease. They are separate entities and ought to be approached with time and care if one is to absorb them and use them properly.
Many often come to confuse modes with scales and vice versa, and while they are theoretically very similar, when you get down to it you realize that they are in fact very different and that the former is wholly indebted to the latter. A mode, instead of being a scale in its own right, is a permutation of a scale.
The modes are worked out in relation to the major scale and this is really where all western classical notions of harmony and what sounds right to our ears come from. The Ionian mode is this very same major scale. So, if we were to say that something is in D Ionian, we would simply be saying that it uses the D major scale throughout without any variation.
With each mode being a separate permutation of the major or natural minor scale on which it is based, it ought not to be hard to see how this can have a very direct influence on what scales to use over what chords. Each mode will offer its own emotional, harmonic, tonal, and melodic aspects that are oft called upon to evoke certain things.
Much like paints, they can be used by composers, musicians, and improvisers throughout the western sphere to paint certain things, just as they can be used by you to portray what you desire to portray.
Final Tones
So, there you have it! Hopefully, you are now feeling somewhat wiser about what scales to use over what chords, or at least are feeling better able to think about and talk about these things with yourself and with friends and online resources, provided the vocabulary with which to engage in polite discourse.
Go off and experiment with as many scales as you can possibly conceive alongside as many combinations of key signatures and chord patterns, making sure at every point to ask your ears precisely what they think and feel so that you are staying as true to your conception of equilibrium as possible.
FAQs (Frequently Asked Questions)
The easiest and the most fruitful way to use chords and scales together is to use your own ears and fingers to see what works for you and what sounds best to your own ears. Rather than simply following mantras and doctrines from guitar websites (like this one in fact) it is much better to apply your ears to each situation and work out what feels and sounds best to you. The best piece of advice I could offer any prospective guitarist is to stay true to one’s own ears and heart and soul as much as is possible. If you are using scales and chords together and they are sounding good to your own ears, then you are doing it right!
It would be impossible to answer such a question without an accompanying encyclopedia of possible combinations between all of the scales in the western world and outwards alongside all the different chords and key combinations. Soloing over the key, however, will be a lot simpler than with chord changes and is a perfect place to start. The best way to work out the key is to play along with a tune and see what notes work and then make a note of them yourself – you can also google the key and, if the song is popular enough, it will usually appear before your eyes. Pentatonic scales are an apposite place to begin when learning to solo over songs in whole keys, with the major pentatonic and/or minor pentatonic doing a more than ample job of filling the gaps for you.