Are you still playing a scale if you don't include every note in said scale?

Question

For instance, if you're playing C major, and instead of playing C D E F G A B, you play C D E F G A, or C D E F G, would that still be considered playing in that scale or key? Because I doubt that most music literally just repeats the exact notes found in a certain scale over and over again to create a melody, otherwise most music would sound the same, right? It seems like when someone comments a scale or key that a song is in, the notes usually aren't perfectly arranged in the way that you'd expect that scale to be in. Like, there will be other notes interspersed in that aren't part of that scale, but it is still considered in that scale or key. Also, what if multiple instruments are playing simultaneously? Would you judge the melody's scale by each instrument, i.e. the guitar is in C, the bass is in Gb, etc., or do you judge it by the simultaneous notes just as they appear? Because that seems like it would be incredibly confusing and hard to analyze, and I don't think you'd be able to really judge its scales unless the instruments were playing similar notes or something. I'm sorry if these are stupid questions but I'm having a difficult time understanding scales and keys as a beginner.

Answer 1

Hi, excellent question- it seems to me that your confusion is caused in part by mixing up the definitions of a "scale" and a "key". I'll stick to your example of C-major to explain.

A scale is a specific sequence of notes organize by pitch. The C-major scale as you know consists of the progression C D E F G A B. To play the full scale, you'd have to play the all these notes- that is the sequence that defines the scale. Any notes other than these are NOT part of the C-major scale.

A key uses a scale to establish the notes that comprise the harmony and melody of a piece of music. As you mentioned above, you could begin playing the C-major scale but stop at A or G. You could also begin at D instead and go up, or go from B down to C, or play any combination of these notes in any order of any length! In these cases you are not playing the C-major scale, but you *are* playing in the key of C-major, because you are playing the notes that make up the C-major scale.

Notes outside of the C-major scale (Bb, Eb, etc.) are not part of the C-major scale but can still be used in melodies when playing in the key of C to add variety to one's playing.

It's safe to say that multiple instruments playing simultaneously will typically be in the same key. Even if they are playing different notes, the notes they play can be found in the same scale. For example, if a bass is playing a C and the guitar is playing an E repetitively, they could both playing in the key of C.

I hope this helps!

Cheers,

Diego

Answer 2

The simplest answer: songs are made of keys which are determined by the notes within the scale.

Using your example of C Major you have CDEFGAB, but if you are writing a melody and completely leaving out F and B it becomes the C Major pentatonic scale (CDEGA). You can choose to play the pitches in any order and frequency of appearance, but to change from the scale/key of C Major you could not use F or B, otherwise, it’s just C Major.

Within the C Major scale/key you may choose to have pitches outside of the key, like a periodic F# or B flat. If these occurrences are infrequent, they are considered non-diatonic pitches, chromatic pitches, or possibly creating a secondary dominant to temporarily showcase a different, closely related key. Non diatonic pitches may also be used to modulate from C major into a completely different key and stay there.

If multiple instruments are playing simultaneously, it is usually still distinguishable that they are in the given key with probable non diatonic variations. If it is clear that the instruments are playing in distinctly different keys, this is considered polytonal (more than one key played at once). The piece may also be written in an atonal style which means there is no established key.

This is not a stupid question. Music theory classes typically build to an understanding of how to analyze music through an understanding of scales and keys, then diatonic chords within each key. There are a lot of variations and depending on the composer there may be more than one way to analyze a single chord.

In summary, tonal composers write in the chosen scale to create the key of their piece. They add color to the scale and chords through non diatonic pitches, secondary dominance, or modulating to a different key.