How to choose a key when you compose a song ?

[Stromkraft]

Its not DNA its repetition.

I didn't mean physical DNA, but cultural DNA. Still makes my point. Everyone can do it!

[Stromkraft]

Beginners can just jam around and that's just fine. Slowly learning what sounds good.
But that is not what you said. " choose 2 chords then find out what key they are in."

All I'm saying learning enough about basic chord structure and how keys are constructed and the role of chords in different positions isn't rocket science. If you can count to 12 you can learn enough to be dangerous. If you want to.

It's the established schools of teaching this quite simple stuff that makes it more difficult to learn than what it really is. It may be hard to learn the finer nuances of classical composing, but basic music theory is not hard. It's just boring for some people. People like you claiming it's hard also doesn't help.

I'm also saying it's not necessary to learn this, which you seem to also say. I think knowing about keys, scales and other parts of music theory is sometimes very useful to get one out of an impasse, but it's not strictly necessary in order to make music. It's also not that hard if you actually want to learn it.

[stringtapper]

I assume that you with the "first chord" mean the tonal? But playing only the tonal won't reveal much about the key. Especially as you consider all keys are related to each other and the tonal of one key is the dominant or subdominant in another.

The word is "tonic."

[Stromkraft]

I assume that you with the "first chord" mean the tonal? But playing only the tonal won't reveal much about the key. Especially as you consider all keys are related to each other and the tonal of one key is the dominant or subdominant in another.

The word is "tonic."

Right. Thanks.

[Coupe70]

[Coupe70]

To contribute something to the original question:
Maybe not when 'writing a song', but when 'producing a track' I sometimes begin with a bassline.
I choose a bass sound and find out at which note it sounds best (or maybe "FAT").
I then build my bassline around that note.
So the in some way the bass sound I choose determines the key of my track.

[dysanfel]

Chose a key that flattering to the vocalist.

[login]

To choose a key you have to know how each key/scale sounds.

majors, sound happy. Minors sound nostalgic. That is common knowledge but between them some sound different.

greek modes also sound kind of different. But then come the ones which have more of a "sound" to them: pentatonic, minor pentatonic and exotic ones as hungarian minor or aekebono.

So I would suggest to choose any key and compose with it, improvise with it and learn how it sounds. Once you learn how they sound you will be able to choose a scale depnding on the mood or goals you have for your song.

Obviously one way to explore all this is to look up what key/scale some of your favorite songs are in so you can check those scales and use them too.

I will highly recommend this video course too, specially for beginners: https://www.groove3.com/Piano-Instructi ... -How-Modes

You can get a lot out of it if you keep trying to improvise.

[nowtime]

login it sounds like you are confusing key with scale as if it were the same thing. What you say is true, that the different scales and modes have different flavors and feelings.

It becomes even more magical when you discover that each of those scales and modes will have a different feel for each of the 12 possible keys or tonics. Maybe not for every instrument, but many different sounds/instruments will have a slightly different feel in various keys. C major just sounds and feels different than F# major even though it is made up of the same intervals. Again maybe every key will not be noticeably different on a certain sound, but you will find that there are certain keys that ring differently. I don't know if it is just resonant frequencies or something else.