Music Theory

Sometimes you can just figure it out by counting. In your specific example a Dminor7 will contain a basic Dminor, which based on the minor intervals is D-F-A, plus the 7th which is the C. With enough practice, you can learn to count it very fast, or even learn it by heart without needing a flashcard.

I'm the kind of person who doesn't like memorising things, I prefer to learn the underlying rules and then count my way. Even when playing the guitar (which I completely suck at), I'm so bad at remembering chord fingerings that I sometimes have to reconstruct them.

On the Piano i go from what i know and transpose the chord, until eventually it is just in my head. For the chords in major minor it is pretty straight forward. a major chord has the large third, as major has the half tone step between 3-4 and 7-8. the minor chord is half a tone lowet on the third because 2-3 and 5-6 are the half steps in minor. Since the fifth is identical in both, the 7 accord is one whole tone below the base tone. In case of the 7maj it is just a half step lower.

So a Dmin7 is D, F, A, C

A D7 is D, F#, A, C

On the piano it is easiest though, because you can see the ladder and transposing just needs to mov the fingers up or down a bit.

As you improve in music theory, more and more information will become internalized, just as someone learns words instead of seeing the individual letters that form those words. A dm7 becomes a “word” that you can use in a sentence (i.e. a phrase or chord progression). Ultimately, you have to become more fluent with the basics (e.g. intervals, keys, all the chords, and so forth) before you can use them poetically, from a music theoretical perspective (that is, one in which you know why certain things are working).

I think it’s wise to try and remember as much as you possibly can. The piano will help. The more you remember, and the more you understand, the easier it becomes.

Source: I have a Ph.D in music theory and work as a prof of music theory.

I think everyone will probably have their own methodology, but I tend more towards having to memorize these things to the point they're instinctual.

For me, the theory and doing it on paper is easy, where I struggle is conjuring this stuff real time when improvising.

The hack I'm using now for chord spellings is that I have all my diatonic 7th chords memorized in C. So if I need to grab a D7 arpeggio, I just need to raise the third of the Dm7 I have memorized. D - F - A - C --> D - F# - A - C.

As stupid as it sounds, having the extra syllable of "sharp" or "flat" in my head really slows down my processing, hence basing it all on modifications to the C major chords.

I mostly use a piano to learn my chords. I'm not sure if you have a piano, but since you mentioned practice, I'm going to asume that you do.

I first started learning about chords when my piano teacher taught me what they were and what's a major and a minor. They taught me the intervals, but I wasn't too sure what they meant at the time.Then they told me to go find the chords of some songs and to play along.

After that I kinda understood what the intervals in the chords meant, so I looked up what were the intervals of some other chords. I learned by heart what they were so that I could play them on the piano.

The catch is I'm not able to tell what notes are in a chord without a piano though. I can try to visualise it in my head, but I wouldn't be able to say immediatly what notes are there without playing it.

Since I mostly compose with a piano, or at least had a keyboard on screen, I never really had to think about it, so yeah that's about it for me.

As for the diatonic chords, the way I would do it is to learn and remember what types of 7th chords are in a major and minor scale so that I could find them in these types of scales.

TLDR: I would just remember the typical structures of diatonic chords in major and minor scales and find the notes once I play them on piano.