Are accompanying instruments typically playing notes from the current "main chord"?

Question

Forgive me if I'm using incorrect terminology. I'm currently learning some music theory from HookTheory.com. They're talking about how songs can typically be broken down into a melody as well as a series of accompanying chords. (I'm aware that this isn't a hard-and-fast rule, but their examples from pop music makes this seem very common.)

When I'm hearing a bunch of instruments in a song that are NOT playing the melody (e.g. a guitar, a synth, and a bassline), are all of these instruments typically simply playing selected notes from the current accompanying chord?

Answer 1

In a way, what 'the chord' is at a given time is, by definition, the notes that are being played at that time - so yes, the accompanying instruments will be playing notes in the chord - but only because the chord is the notes that are being played... (etc. etc., round in circles...)

If we followed that idea strictly though, it would mean that 'the chord' could potentially be changing every time a note stopped or a new note was played. What tends to happen is that people consider the notes in the chord to be those notes that are being played consistently or repeatedly (so not every note played is considered to be part of the chord) for a period of time until it becomes clear that the set of notes being played (and especially the lowest note) has changed, signifying a new chord.

If we flip the logic one more time... yes, it is fair to say that accompanying instruments will typically be playing the notes in the chord, although there might be other ornamental or decorative notes in there.

If we extend this idea - it would even be possible to consider that even an unaccompanied solo instrument was following a chord progression, for example if it was arpeggiating notes in from a sequence of chords in turn.

If you read the chord progression from a transcription, and then listen to a recording, you will sometimes find that not all of the notes in the written chord are present or prominent in the recording. This can because there's a presumption towards writing triads - e.g. C Major - but some modern songs survive on sparser harmonies, especially bare fifths (such as power chords) or sometimes a bassline may play a harmonic root that isn't expanded into any particular chord.

Answer 2

I'm going to give you a very simple answer. (Some might say simplistic! But I hope it is useful for you as you begin your studies of music theory.)

Often, yes -- but imagine a bass line. It's common, and lovely, to make the base line more melodic by inserting some notes that aren't part of the triad.

Other voices in the ensemble can do that too -- but it's SO common in the bass line that I think it will be easier for you to appreciate this when you listen to some bass lines.

Answer 3

All the notes begin sung or played at the same time are part of the chord. So this means the note played by the bass guitar, all the notes of the piano, and the note the singer sings is all part of the chord. When the song changes from one chord to another, we call that chord progression. Most every song (except things like plain chant or African drums) have chord progressions. The notes the singer sings sometimes sounds good with the chord (we call that consonance) or sometimes sounds bad with it (we call that dissonance)... and sometimes that dissonance is the best part of the song- it's the part that often gives you goose bumps.

So to answer your question about the melody and chords. Sometimes you will want the melody to play the same notes as the chords in order for the listener to hear consonance, but sometime you will want the melody to disagree with chord in order to create dissonance. That melody note will still be part of the chord, even if it's dissonant, but it's also thought of as its own melody (other instruments don't have to play that note just because the melody sings it).