The internet search engine seems not to recognize it, so I cannot search for it there! I had assumed it was "augmented" but am now very unsure. Thanks

  • 13
    Diminishing returns from a search engine, eh? – thrig Feb 9 '17 at 15:51
  • 1
    @thrig - searching for nothing (o) was never going to be easy... – Tim Feb 9 '17 at 15:55
  • 2
    I cannot think that this has not been asked before. – Neil Meyer Feb 9 '17 at 16:17
  • 3
    @thrig Availability or lack thereof of any information via a web search is not to be a criterion on Stack Exchange. We want to be a (top?) hit on search engines, which means we want to have the answers here even if those answers are available elsewhere. – Todd Wilcox Feb 9 '17 at 17:30
  • 3
    "The internet search engine"? – Lightness Races in Orbit Feb 9 '17 at 19:52

Augmented is '+'. The 'o' is diminished. With your example of F#o the notes involved are F#, A, C. The diminished seventh chord will include Eb, although I can't remember ever seeing the symbol 'o7'.

  • 1
    Or at least F#, A, and C. I think most people would omit the Eb unless the chord name had a 7 attached? – L3B Feb 9 '17 at 15:59
  • @L3B - thanks, edited. Funny, but I often include that bit when a dim chord is on a chart! – Tim Feb 9 '17 at 16:10
  • F#° pretty much implies Eb, as this note does not add any color, and I don't recall having ever seen the symbol °7 (but I have seen +7). Also note that this is a diminished seventh, not a minor one. Finally, you surely cannot play E natural with this chord though, or the symbol would have been that of a half-diminished chord, another harmony. – Alexandre C. Feb 9 '17 at 18:19
  • @AlexandreC. - exactly. the half dim chord is subtly different, often called m7b5. – Tim Feb 9 '17 at 18:30
  • Not subtly, but completely different. F#° is eg. a V in G (and also in other tones), and F#m7b5 is a II in E minor. – Alexandre C. Feb 9 '17 at 18:32

More specific to the question of what the degree sign means is that yes it is a diminished chord and that means that the chord has the notes that form a minor third from the root and a diminished fifth from the root.

So, as Tim mentions, in this case, it will be F#, A (minor third) and F# to C (diminished fifth)


Different editors/publishers seem to notate certain chords differently, but a fairly common scheme is to describe an C diminished triad (C-Eb-Gb) as C(b5), an C half-diminished 7th (C-Eb-Gb-Bb) as Cm7(b5), and a C full-diminished 7th (C-Eb-Gb-Bbb) as C°. Note that a C full-diminished-7th is enharmonically the same as a diminished triad with an added major 6th (C-Eb-Gb-A), and because it would be weird to describe a note nine frets up as a "seventh" (rather than a major sixth) but it would also be weird suggest that the top two notes of the chord are only separated by a second when they're three frets apart, using the C° notation is a simple way of saying that chord note contains pitches that are spaced upward at intervals of three frets starting at C without having to worry about what those notes should be called.

  • I'd spell C7b5 as C E Gb Bb. Wouldn't it be C Eb Gb Bb for half dim, Cm7b5? – Tim Feb 10 '17 at 8:32
  • @Tim: Corrected. The way I tune my guitar, half-diminished chords and full-diminished chords are easy to play and sound great, but the major-7-flat-5 is quite a bit more awkward so I sometimes forget about that chord. When writing out my own tabs, I use a slashed circle for half-diminished chords since I find all the stuff with parentheses harder to read while playing. – supercat Feb 10 '17 at 15:25
  • Sometimes see it written Cm7-5, obviating parentheses. Slashed circle is good - can't find it on my qwerty board, though! Same with 'degree'. – Tim Feb 10 '17 at 16:22
  • @Tim: The Javascript thing I wrote for my guitar tabs takes chord names in ASCII and then substitutes suitable characters for sharps, flats, slashed or unslashed circles, etc. So typing Abho7 will produce a fingering symbol with a big 6 over it showing the index finger across five strings (6th fret) and the middle finger on the next fret, and something like A♭⊘₇ (I forget which circle-slash character I used) underneath it. – supercat Feb 10 '17 at 16:29

Not the answer you're looking for? Browse other questions tagged or ask your own question.