In this instructional video, I saw that G can be connected to E7, and it is often used. Belongs to Secondary Dominants.
But I click on the suggestion in SCLAER, and there is no option for the chord E7.
That is, it is not very convenient to select Secondary Dominants
Likewise, there are Borrowed Chords.
Wouldn’t it make things easier if the Scaler had two buttons ready to target Borrowed Chords and Secondary Dominants. Let everyone try.
There is a way to find the secondary dominants on the MOD page, it is just no obvious.
To do this:
Having decided on the key you are using (in this example G major scale so the key is G)
go to the MOD page, and slect secondary scale from the drop-down menu.
Then select your key by clicking on it for the secondary scale. Because my original key was G, I have clicked on G again to display the secondary dominants.
Hope this helps
thanks. I tried it and found a few things.
The second chord is G, I’m going to be D7
When I moved to the back G, it did show D7, but the sound was on the high side. Not nice.
So I chose G at the source on the left. At this time, D7 appeared, and the sound was right.
If the pitch is too high have you tried editing the chord in the Edit page?
I think this could avoid having to change the key of the secondary scale
OK.please look:
Are Secondary Dominant chords only available in major keys?
What does “and their modes” mean?
The original words in the introduction:
Secondary Dominant chords are a great addition to the 7 chords we normally see in major keys and their modes
For modes, watch Jake’s videos on modes, he has a whole bunch of them, and they’re great.
Think of a secondary dominant like “the 5, of the 5” (5 being V)
in C Major, your I chord is C Major, your V chord is G Major, now to find the secondary dominant, you treat that G as if it is your I chord, and from there go to the V, in G Major, the V chord is DMaj <— this D is what is called the secondary dominant.
So if you want to end on the I chord of your current scale, coming from a secondary dominant, you’d go V/V > V > I.
~ V/V just means 5 of 5, it tends to be written like that, the first one is the chord your playing, the second where it came from, so V/ii means the 5 of your 2, IV/iii means the 3 of your 4 etc.
~~ Another note, the V is the Dominant scale degree (it’s the “name” of V, the rest are listed below, using Major as the reference).
I - Tonic
ii - Supertonic
iii - Mediant
IV - Subdominant
V – Dominant
vi – Submediant
vii°– Leading Tone
The confusing thing in learning about secondary dominants is that the word dominant is also used as a name for a certain chord. Example: adding a B note on top of your C chord, that makes it a C Major 7 chord (C, E, G, B) (written as I-Maj7 in C Major, because C is your I) , but if you add a bB instead (1 note/semitone/“a half step” down from B), then that chord is called C Dominant 7 (which, if in C Major, would be written as I-7). This has nothing to do with the dominant scale degree, they just have the same word in the name, I remember this being confusing for me too 
(the same word being used for multiple different things is a common thing in music theory, it’s good to keep that in mind)
So the V7/ii in your screenshot specifically means playing a dominant seventh chord (that’s what the 7 in V7 stands for) on the 5th scale degree (that’s what the V in V7 stands for) of the ii chord (2nd scale degree), which in C Major would be the note A7. Cause you’d go:
“Start at C”
“find your ii, that’s D”
“find the V of D, which is A”
“play that A chord as a dominant seventh chord, which makes it A7”
for the question: “Are Secondary Dominant chords only available in major keys?”
I don’t have the knowledge to answer this properly, as I’m not sure if you mean “from the key you are currently in”, or “in the key that the secondary dominant comes from”, and I think there was something about how minor v’s don’t “function” like major V’s (look up functional harmony and/or roman numeral notation, it’s there somewhere) but I can’t remember the specifics.
P.S. I have no formal theory education or anything, but as far as I know this “should” all be correct, not counting formatting formalities like using the ° symbol for the Leading Tone scale degree, which I assume to be technically incorrect, but for the purposes of this explanation combined with the way it’s presented in Scaler it makes more sense.
I just want to know if if not major music. Is it possible to use Secondary Dominants.
Yes, this guy’s video is good, I also know about it on SCALER forum.
Amongst its various potential functions, I think the Scaler forum (apart from discussing Scaler and helping other users to find their way around it) is useful for ‘signposting’ - pointing folk to information sources where they can find out more about music or music technology not specifically associated with the Scaler application.
However, I think the scope for it to be of become a general learning resource in its own right is perhaps limited; and whilst board folk will happily respond to learning ‘blocks’ in understanding tricky things in a self-learning process, it can’t IMHO replace the various on-line materials for that purpose - ultimately it’s ‘do it yourself’, maybe turning here if you get stuck.
.
Could someone point me to
please?
I do not have much formal training in music theory so I would welcome the chance to expand it.
Just found this mnemonic I Don’t Particularly Like Modes A Lot to remember the order of modes
Ionian
Dorian
Phrygian
Lydian
Mixolydian
Aeolian
Locrian
Music Modes: How to Enrich Your Songs with Modal Color
on the Landr blog
Here
https://signalsmusicstudio.com/author/jake/
He is guitar focussed. Scroll through his videos and you will find some really useful stuff … check out his vid on ‘drones’ for example. He has various vids on modes and modal interchange, etc.
It’s maybe worth checking Danny Gill’s ‘mode’ series in Lick Library, now streamable. I was interested in modes, so I got his 8 DVDs
Don’t tackle Locrian if you have a hangover 
There is often a discussion as to whether parallel or derivative approaches to the mode are better. I use both. To me it’s handy to know if I play a caged 1st position scale I change one finger for dorian, another for mixolydian and another for lydian. This sort of visualisation always helps me to do things more instinctively.
thank you very much!
Thanks Yokrerman, much appreciated as I have only limited musical training
You might find this useful. I certainly did.
It’s slightly piano focussed, but an excellent reference document. It’s £0, so well worth downloading.
Thanks @Bagatell , for the link.
You can download all the examples direct to Musescore (also $0).
