You where not taught modes, you where introduced to modes.
And you were not taught how modes are used, you were introduced to one method of constructing them.
Please note that just like constructing a bass and playing a bass are two different things, constructing modes and using them are two different things.
I see lots of people who have only been introduced to a method of construction of modes who think that they know or understand them. There was even an argument on this forum between a very young student who had been introduced to modes as "D dorian is the notes of the C major scale from D instead of C" and a very very experienced player.
1. Are you able to look at a series of chords and determine what key they are in?
2. Are you able to look at a series of chords where the first few are in one key and the next few are in another key and determine exactly where the key change is?
3. Are you able to play through a series of chords and know what notes to play to outline the chord changes?
4. Are you able to play through a series of chords where there is a key change and know what notes to play to anounce the key change?
5. Can you tell someone what the seven chords of a major scale are and which are major, which are minor and which is diminished?
Those five things are way more important than modes.
Ok.
Key of C.
Chord is Dm.
You can play D Dorian mode.
But if improvising I would play the notes from the C Major scale stressing maybe the 3 of the chord (F), because I believe that this is the most important note in that chord, and if it was a Dm7 I might play the 7 (C) because I believe that this is the next most important note.
If I was playing a bass line, I would start the measure with the D, because that is the 1 of the chord, and I am the most boring and typical bass line player out there, and I would move to the next chord by either using Dm chord tones or C Major notes.
Now. Slow down and take a breath.
Some bass players like to play the root note of each chord with their index finger, and shift hand positions for each chord. That way they always have their pat memorized phrases under their fingers, and they know the locations of each of the chord tones, in relationship to the index finger/root note position. Just like a guitar player shifting hand positions with each chord. So if you are playing in the key of C, and playng the Dm7 chord, you can move your index finger to the D (third string fifth fret), and play the notes out of the Dm7 arpeggio. So...If you know the fingering of the D Dorian mode, FROM THE INDEX FINGER, you can play the notes of the key of C, or the C Major scale, (or the C Ionian mode), just by playing your memorized D Dorian fingering. In this manner, you can mix and match Dm7 chord tones and C Major notes. But, it does not mean that you are really playing the D Dorian mode, even though you are, what you are actually doing is playing notes from the key, but you are using the D Dorian mode fingering, along with the Dm7 arpeggio fingering, to create a melody or bassline. Many bass players are happy forever playing this way. They think that they are playing modes, and they think that they are outlining the chord changes, and they are, but they are doing it in a way that is only a little more advanced than moving rock guitar power chords around.
Ok. Another breath.
Many advanced players like to play through a series of chord changes keeping their hand in one position, without shifting it, so they learn the arpeggios in each position for each chord, and play through chord changes using chord tones and key notes without jumping around. They are not thinking modes or using mode fingerings, they are playing chord tones for important notes and landing notes, and connecting those important notes with other chord tones or key notes.
When you see a bass or guitar or piano player playing through chord changes but staying in one place on the fingerboard or fretboard or keyboard, this is what they are doing. As the chords change, they are playing different inversions of those chords based on the position they are in.
Take a chart of music that is 4/4 with one chord per measure, and pick a "five fret zone" on the fretboard/fingerboard, look at the first chord and play the lowest note of that chord in that zone, and play four chord tones up for that measure, then play the next higher closest note in the next chord. I mean, look at where you are on the fretboard, determine the notes in the next chord, and since you are playing up, play the next cord tone up from where you are. Keep doing this until you run out of room in your five fret zone, and start down. The same way. Chord tones in order, then the next closest chord tone from the next chord, then when you get to the lowest note, and turn up again, for the next chord, start on the next chord tone, but play up four key scale notes from that chord note, then look at the next chord, and jump up to the next closest chord tone to start the next measure, but continue moving up four key notes. Switch back and forth playing chord tones (arpeggios) and key notes.
Do this for different five fret zones, and different charts, and mix up the chord tones and key notes, and then go through the entire chart starting every measure on the 1 of the chord, then the 3 of the chord, then the 5 of the chord, then the 7 of the chord.
Eventually you will discover that you can play more fluid lines, controlling what chord tones you are starting with and landing on, all over the neck, instead of a few pat locations.
Are you playing modes? Well...you are playing notes from the key...and chord tones...yes, you are playing "modes", but you can do it by thinking of the chords and the one key scale.
Too many people get caught up in D Dorian being the notes of the C Major scale starting on D, well let me be the first to tell you, that D, E, F, G, A, B, C is C Major scale starting on D, the D Dorian mode starting on D, and the G Mixolydian mode starting on D, etc. How many songs do you know where the melody starts every measure on the 1 of the chord and plays up the mode scale until the next measure? It is way more important to outline the chord tones, "playing through the changes", by playing chord tones and key notes, than to think about playing a different mode scale each measure.
Most people stop one third of the way. They learn how to determine the key notes for a sequence of chords, and they remain confused on the modes, and they never learn the locations or sounds of the chord tones. So they blow through the chord sequence playing random notes from a major scale fingering pattern and end up sounding like a scale exercise. Some others learn walking basslines by playing only arpeggios, and never mix in a series of key notes here and there.
I recommend that you learn how to outline the chord changes first, with chord tones and key scale notes, while continuing to learn about and think about modes, and you may end up understanding modes, but not ever actually using them.
tim99.