C# and Db - what's the difference?

The major and minor scales in C are generally among the first things you'll learn, regardless of your instrument. You may well then afterwards progress onto other scales, say the Db Major Scale or the C# Harmonic Minor Scale.

Now everyone knows that C# and Db constitute the same black key on the Piano - they are in all harmonic senses the same note, but curiously called different names. In the case of chords, we similarly would label the constituent notes of a Db major chord as (Db, F, Ab) instead of (C#, F, G#).

The question arises then, as to why we name these identical notes differently and if there's any coherent thought or reasoning behind this?

Naming Notes of Scales

Let's briefly introduce some basic definitions here.

Tonic: Aside from rare and conscious exceptions, most songs have a specific note as their tonal centre, which is also called the tonic note. The quick test for this is identifying the pitch which never sounds 'wrong' over the song in question.

As an example, one can play the tonic note D over the entire masterpiece of Pachelbel's Canon and it will always sound harmonically pleasing.

Degree: Relative to the tonic, the notes of a scale are often labeled with numbers delineating their correspondence to said tonic note.

For example, the notes of the C major scale (C, D, E, F, G, A, B) can be labeled {1, 2, 3, 4, 5, 6, 7}, reflecting the choice of C as tonic. The expression 'scale degree' is used for these numerical labels.

Such labelling requires the selection of a 'first' note. There is no universal '2nd' degree, rather the 2nd degree of a scale depending on the tonic note. The 2nd degree of C is D, the 2nd degree of D would be E, and so on.

These scale-degree labels are not intrinsic to the scale itself, but rather to its modes. If we were to choose A as the tonic, then we can shuffle the notes of the C major scale, now using A as the first degree, B = 2, C = 3, and so on. When we do so, we create a new scale called the A minor scale.

If we select A as the tonic in the A Major Scale, the following notes will be A, B, C#, D, E, F#, G#, which can also be labeled {1, 2, 3, 4, 5, 6, 7}.

The following image(comes from EUMLab's Piano Handbook) displays C Major, A Major and A Melodic Minor(Descending) scales, with {1, 2, 3, 4, 5, 6, 7} being marked as {U, M2, M3, P4, P5, M6, M7}.

Scales Piano

The scale degrees of a heptatonic (7-note) scale can also be referred to using the following terms:

  • tonic
  • supertonic
  • mediant
  • subdominant
  • dominant
  • submediant
  • subtonic

Also commonly used is the solfège naming convention, in which each scale degree is denoted with a syllable. In the major scale, the solfège syllables are most commonly; Do, Re, Mi, Fa, So, La, Ti, Do.

Now, in writing the notes of a scale, it is customary that each scale degree be assigned with a successive letter. The A major scale is written A–B–C#–D–E–F#–G# rather than A–B–Db–D–E–E#–G#.

Applying this axiom, this explains why under a A major scale, we have no choice but to name the 6th degree as F# minor instead of Gb minor.

Circle of Fifths and how notes are named

If you're not at all familiar with the Circle of Fifths, we duly point you towards this article: 5th Circle

First of all, its important to remember that depending on the instrument, people generally tend to favour certain keys over others. This may be because certain instruments are tuned in a way which lends itself to particular key signatures. The key of E is very popular in guitar composition as many of its degrees can be played easily with open chords. Theoretically, certain keys are preferred because they're simply more orderly to work with. For pianists, it is rare for example, for a song to be composed in Bb, which contains 5 sharps and is considered somewhat as a 'remote key'.

For the Db major scale, if we were to follow the rule of assigning each degree a successive letter, the notes would be named as Db, Eb, F, Gb, Ab, Bb, C. However, if we named it as C# major, each notes will be named as C# D# E# F# G# A# B#.

As a result, we prefer to use the enharmonic equivalent Db major because it has five flats as opposed to the seven sharps of C# major. This is true of essentially all composers, except for a few notable exceptions in classical music.

5th circle

The Circle of Fifths is commonly used to represent the relationship between diatonic scales. The number of sharp or flat symbols on the inside of the circle represents the amount of sharps or flats in the key signature of that particular scale. From quickly glancing at the circle, we can easily register that Db has 5 flats while C# has 7 sharps.

Starting from the top and proceeding clockwise by ascending fifths, the key of G has one sharp, the key of D has 2 sharps, and so on. Similarly, proceeding counterclockwise from the top by descending fourths, the key of F has one flat, the key of B♭ has 2 flats, and so on. At the bottom of the circle, the sharp and flat keys overlap, showing pairs of enharmonic key signatures.

In the process of writing musical scores, the order of sharps that are found at the beginning of the staff line follows the Circle of Fifths clockwise from F through B. The order is F, C, G, D, A, E, B.

The way this indicates the key signature is as follows: if sharp is shown as F, we know from the Circle of Fifths that this must then be in the key of G. If the two sharps are F and C, this can only be possible in the key of D major.

For notating flat notes, the order is reversed: B, E, A, D, G, C, F. This order runs counter-clockwise, where moving around the circle means adding a flat.

How to find Scales and Chords in Ukulele Toolkit and Guitar Master

You can find scales and chords easily on both the Ukulele Toolkit and Guitar Master apps.

Scales

Switch to Scale tab, and tap the icon on the upper right hand corner of the screen. There are 108 kinds of scales for you to explore, ranging from the standard majors and minors to the exotic Chinese and Byzantine scales! At the touch of a button you can change the tonic and thus the notes of the scale, making it very easy indeed to see how certain note names change depending on the tonic.

scales

Chords

Long press the Chord tab and switch to "Find Chord by Key". Select A major as the key signature and see how the iv chord of A major changes to F#m instead of Gb minor.

Tap the zoom button on the top right of the chord diagram to explore details and more fingerings.

chords


Learn more about the Circle of Fifths and how notes are named on Wikipedia:
Circle Of Fifth Scales

Download the latest version of Guitar Master and Ukulele Toolkit:
Ukulele Toolkit Guitar Master

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