What is an augmented seventh chord? Size of the seventh

[johentsch]

The mapping from chord features to chord types goes as follows:

Root	Type	Inversions	Chord type
RN		, 6, 64	Major triad
rn		, 6, 64	Minor triad
rn	o	, 6, 64	Diminished triad
RN	+	, 6, 64	Augmented triad
RN		7, 65, 43, 2	Dominant seventh
rn		7, 65, 43, 2	Minor seventh
rn	o	7, 65, 43, 2	Diminished seventh
rn	%	7, 65, 43, 2	Half-diminished seventh
RN	M	7, 65, 43, 2	Major seventh
rn	M	7, 65, 43, 2	Minor major seventh
RN	+	7, 65, 43, 2	Augmented seventh

The only problem is, that for all seventh chords the size of the seventh is defined but not for the augmented one. I suggest to fix it to always have a major seventh because in the case of the minor seven the chord is so much more likely to be analysed as an alterated dominant V7(#5).

[adriannagel]

Is it not possible to have two different symbols for the augmented seventh chord like RN+7 (-> which is a minor seventh) and RH+M7 (-> which is a major one)?

[apmcleod]

For me (as someone using the dataset with a music performance background, but no real classical theory education), a brief search when using the data lead me to this page (and other similar pages) that suggest that a standard augmented 7th chord has a minor 7th. The alternative seems to be commonly called "Augmented major 7th".

It's important that a naive user doesn't make the wrong assumption given the labels.

So, I think @adriannagel's suggestion is a good one.

[apmcleod]

Or at least, if we use RN+7 to mean something other than an augmented triad with a minor 7th, it needs to be made extremely clear.

[johentsch]

Great everyone, that's what we agreed on.

Solution: V+7 has a minor seventh, V+M7 has a major seventh. New table:

Root	Type	Inversions	Chord type
RN		, 6, 64	Major triad
rn		, 6, 64	Minor triad
rn	o	, 6, 64	Diminished triad
RN	+	, 6, 64	Augmented triad
RN		7, 65, 43, 2	Dominant seventh
rn		7, 65, 43, 2	Minor seventh
rn	o	7, 65, 43, 2	Diminished seventh
rn	%	7, 65, 43, 2	Half-diminished seventh
RN	M	7, 65, 43, 2	Major seventh
rn	M	7, 65, 43, 2	Minor major seventh
RN	+	7, 65, 43, 2	Augmented (minor) seventh
RN	+M	7, 65, 43, 2	Augmented major seventh