I want to understand how you're supposed to play songs on piano. From what I've seen so far, you play the melody with one hand and with the other hand you play the chords, either as full chords or arpeggios. But how do you know which chords you have to play to fit a certain melody?
I already know a bit of music theory so I tried figuring it out on my own. I looked up Katyusha on piano to see which chords are played. https://www.youtube.com/watch?v=5gMx_Yiut9w
The song is in D minor, and they play the chords in this order:
Amaj 2nd inversion x4 (Db E A)
Dmin x 2
Fmaj 1st inv. (C F A)
Gmin 1st inv. (D G Bb)
Dmin, Gmin 1st inv. , Dmin, Amaj inv. , Dmin.
I assume that some chords are inverted so that the transition between them is smoother.
They play the same melody on the right hand side throughout the video, but in the beginning they only play the root notes of the chords with their left hand, after that they play the chords in different ways, and then they play the complete triads. And this is my question, how do you know which chord progression fits over a melody?
I tried to see if the chord degrees had anything to do with it. The chords in the key of D minor should be: Dmin (i), Edim (ii dim), Fmaj (III), Gmin (IV), Amin (v), Bbmaj (VI), Cmaj (VII). I imagined in simpler songs like this one you only needed to play chords from the key, but here they use an Amaj (A Db E) instead of an Amin (A C E), and I listened to the song with both an Amin and an Amaj, and I think it sounds better with the Amaj. I guess because when a G is played in the melody over the Amaj it forms an Amaj7 which creates more tension.
I also tried writing the chord progression:
i - i - i - V
V - V - V - i
i - III - iv - i
iv - i - V - i
but I can't really tell if this has anything to do with the melody.
So if I take another simple melody like Bella Ciao for example, can I figure out what chords to play from just that?
Or do I just try to see which chords sound good over it?
I guess what I want to know is in which way the notes in the melody relate to the notes in the chord progression?
>tldr: how does music work