: Colorful sounding chords There is a music track that has beautiful colorful chords. I think that they include ninths in each one to achieve the good atmosphere. I'm sure there are another aspects and factors like the chord

I wasn't clear what your question really was to be honest, but I think you were asking how you create such colourful sounding chords, so I've added that question and I'll try to answer it a little bit here.

There are 3 aspects I'd like to talk about, but they both stem from a similar concept of dissonant.

When you hear a single tone, what your ear is interpreting is a pure singular waveform.
When hearing multiple tones at once, you get the beginnings of harmony. in that sense 2 tones at once sounds more rich/colourful than one at a time.

From here there are 3 factors which influence how 'colourful' a chord is.

The intervals between tones
The number of tones
The context of the chord

The interval between tones

I won't go too deep here because it's a very expansive subject, but intervals exist on a spectrum from consonant to dissonant, with octaves and parallel fifths at the consonant end, and minor seconds, augmented fourths and microtones at the dissonant end.

what I'd describe as 'colourful' intervals really depends on your ear, and it's exposure to music. Free Jazz fanatics make a habit of listening to dissonant music so their colourful is much more towards the dissonant end of the spectrum.

Interestingly, there was a time when major thirds were considered to be heavily dissonant, because at the time nobody had heard them in music before.

Perhaps read on before coming back to this point, but the interval part of explaining colour is why a diminished triad with only 3 tones sounds much harsher than a Major 9 which has 5, or even a major 11 which has 6!

The number of tones

When you hear a chord, what you're really picking up on is the complexity of the waveform. when there are 2 tones, you are picking up one interval, when there are 3 tones however, you are hearing 3:

between tones 1 & 2
between tones 2 & 3
between tones 3 & 1

And to make things more complex, 2 waveforms together actually produces a third waveform, which is fed back into the system and combines with the others, though I'm sure someone else can explain far better than I can.

so that's jut with 3 tones, but as you introduce 4, 5 and beyond tones at once, you can begin to understand how chord theory gets so complicated!

The context of the chord

Your mind has a memory of the sounds it just heard, so when a dissonant chord is resolved your mind remembers the chord as less dissonant than it actually was at the time. This has a great number of consequences for what you can do in music ranging from modulation to passing chords to holding tension for long periods of time. 2 examples I'll cite for this are

Stairway to heaven

Second Chord is a min/maj7, which on it's own is a very dissonant chord, but when resolved like it is in stairway comes across as colourful.

Tristan Und Isolde Prelude

The Tristan chord is famous for this piece. The piece itself is one long dissonant never quite resolving chord that takes advantage of your mind holding over intervals from the previous chord

In Conclusion

There are multiple aspects to what makes a chord sound rich, and I have only scraped the surface. I can't remember the proper word, but the Timbre of an instrument is important, the length of time it's played for, how much you've heard the song before (some songs you once loved get boring as you get used to them), your age because you lose your range of hearing as you get older.

In a two word answer, what makes a chord sound colourful?

Your Brain

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