I recently asked another (marked as duplicate) question in which I stated the notes in B7 as being B-Eb-Gb-A. One of the commenters on that question informed me that the notes which I referred to as Eb and Gb are more commonly named as sharps, D# and F# (respectively), instead of flats. Can anyone, without getting too technical (music theory is not my strong suit, please try to keep your answers in layman’s terms as much as possible), briefly explain the following:

1) which note name I should use (obviously, in this particular case, it’s the sharp names)

2) when I should use one note name over the other

3) why one note name is used more commonly than the other

Thank you!

EDIT: I did mean B7 instead of Bmaj7, and I just fixed it. My apologies for any confusion!

  • Possible duplicate of When is a note flat/sharp? or Why do notes have multiple names? – endorph Apr 27 '17 at 10:34
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    And, bizarrely, those # and b that actually belong in the key aren't known as accidentals. They're there on purpose, making accidentals the extra # and b that get added to a key during modulations. – Tim Apr 27 '17 at 11:45
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    The A note you mention in Bmaj7 needs to be A#. Otherwise the chord quoted is called B7 (B dominant 7). The commenter would have been correct in the key of B maj., although if speaking generally, Eb is more commonly used than D#, although F# is found far more often than Gb. – Tim Apr 27 '17 at 16:39
  • @Tim Yeah, I meant B7. I don't know where the "maj" came from—oops. I'll fix it ASAP; thanks for catching that! – cjor530 Apr 28 '17 at 12:45

To simplify the situation: each and every one of the keys is given each of the letter names A to G. In C, with no # or b, they are C D E F G A B. The spacing between each two letter names is T,T,S,T,T,T,S where T=one tone, S= a semitone. That's what we decided sounds o.k. a long time ago. So, C>D=T, D>E=T, E>F=S, etc.It must work for all major keys, in 12EDO (equal tuning). One main reason for this naming procedure is that when music is written out, each letter name needs its own line or space.

So far so good, I hope.Getting on to your B key - the letter names will be B C D E F G A. EXCEPT that to get the spacings correct, # OR b need to be applied.Starting on B, the next note up is a C - of some sort. There needs to be a spacing of one tone from it, so the next note is called C#. From there, it's another tone, we're onto letter D, so it's D#. Next, one semitone away, is plain old E.

Now, it's clear that if the 3rd note (D#) was to be called Eb, there is a problem. In this scale/key, there are TWO notes that we'd call E (Eb and E). Writing it out, they'd both be on the same line/space, and there'd be a lot of cancellation of one for the other. And a lot of confusion, alleviated by calling the 3rd of the key of B D# (which wouldn't otherwise ever have a note written in its own place!)

The same applies for each and every note of each and every key, and although complicated, actually simplifies the situation. Guitarists, from experience, don't seem to have a problem calling a note by either name, but technically in one key there's only one proper name, and in the heat of the moment, it's academic, and only becomes problematic when trying to write the music for others to read.

And that's the simple explanation...

This idea happens in each key,which is why C has no #/b, A has 3#, Eb has 3b, etc.

Your parting question - a note such as F# features in ALL of the major key signatures, therefore it will be far more commonly called that rather than Gb. In the same vein, Bb comes in every flat key (F, Bb, Eb, Ab...) so is far more likely to be met as such rather than its alias of A#.


Chords like this are built by "stacking" thirds. Taking B to be the tonic, C# is a major second above B, and D# is a major third above B. Similarly, E# is a major second above D#, and F# is a minor third above D#. Finally, A is a minor third above F#.

Putting this all together, B, D#, F#, A spells a B7 chord. The simple rule of thumb is to alternate alphabetic pitch names from the root.

By spelling this chord as B, E♭, G♭, A, you ignore that the chord is constructed in thirds, and also ignore that this chord comes from the key of E major, which contains the notes E, F#, G#, A, B, C#, and D#.

Note that this is not a Bmaj7 chord, as suggested in the question. A Bmaj7 would contain an A# instead of an A.

  • I failed to spot the A / A# discrepancy. – badjohn Apr 27 '17 at 9:52

If you are looking at a chord in isolation then, where possible, use names from within the scale of the root note. Hence for B7 (not Bmaj7, see correction below), use notes within the scale of B: B, C#, D#, E, F#, G#, A#, B.

If it is within a piece of music then the key signature may override that. This is particularly relevant for chords which are ambiguous in isolation e.g. diminished and augmented chords. Not only those, for example is CEGA C6 or an inversion of Amin7? In isolation you cannot say but within a piece of music, one name might be more appropriate than another.

Other recent answers to similar questions have given some useful guidelines. For example, most chords are built on triads: 1st, 3rd, and 5th of a scale. So, try to use names that reflect that hence B, D#, F# rather than B, Eb, Gb.

Correction after reading David Bowling's answer. As he says, B, D#, F#, A (however spelled) is not a Bmaj7 chord, just B7. The naming of 7th chords is potentially confusing. For a simple major chord, e.g. C, C and C major are usually synonymous. However, there are three common 7th chords. The dominant 7th often called the 7th is the major triad plus the minor 7th, this is what you have. The notes are not from the scale of the root but they are from the scale of an associated key (a fifth below) for which this is the dominant. A minor 7th is the minor triad plus the minor 7th. A major 7th is the major triad plus the major 7th. This last chord is discordant but can sound good in the right context.

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    Let's not forget the rarer minor major seventh! – Tim Apr 27 '17 at 10:15
  • @Tim I had forgotten it. So, B, D, F#, A#. Can we reinterpret that as something else? – badjohn Apr 27 '17 at 10:36
  • Without making the name a sentence long, no. – Tim Apr 27 '17 at 10:44
  • @Tim I tried but the A# / B made it difficult. – badjohn Apr 27 '17 at 11:53

Here's another way of looking at it.

With your particular chord, both Bmaj7 and Cbmaj7 (C-flat major seventh) sound the same.

The Bmaj7 is B D# F# A#, which correspond to the first, third, fifth, and seventh steps of the B major scale. The seventh step of the scale is A# (B major has five sharps, and A# is the fifth one).

Likewise, the Cbmaj7 is Cb Eb Gb Bb, which correspond to the first, third, fifth, and seventh steps of the Cb major scale. The seventh step of that scale is Bb (Cb major has seven flats).


3) why one note name is used more commonly than the other

Your example of Bmaj7 used a natural note for the chord root. But also consider when the chord root or key tonic is not a natural. For example D# major or Eb major. I believe the convention in this case is to use the key signature which uses the least number of accidentals. D# major would be: D3, E#, Fx, G#, A#, B#, Cx, D#. How awkward is that! (BTW 'x' means double sharp.) Eb major uses only three flats: Eb, F, B, Ab, Bb, C, D, Eb. Try using simpler key signatures to choose between enharmonic spellings. (I'm glossing over cases where the music is ambiguous in terms of key or is very chromatic.)


You "change letters" in correspondence with the chord steps. For any kind of seventh chord, the steps are I-III-V-VII plus modifications. So a seventh chord for Bx (x being an arbitrary accidental) is spelled Bx-Dx-Fx-Ax. In this case, your major seventh results in B-D♯-F♯-A♯. Note that this is the canonical way of going about pitches: when modulating in a particular key, some composers might prefer writing in-key pitches in preference to the "canonical" spelling of a chord. The tendency to do so is weaker when the chord is explicitly named outside the staff as well, though.

Using canonical chord spellings has the advantage that the shape of the noteheads is characteristical for the basic nature of the chord.

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