For a melody harmonization, I wrote a 2 bar bassline using half notes with scale degrees ^1 ^7 3^ and ^5 and wanted to write chords for these bass tones. For the first bass note I chose the I chord. For ^3 I wanted to use iii and for ^5 a V7 to take me back to tonic. For 7^ (second chord) I thought about just having the same I chord but with its 7th in the bass. I am currently learning harmony and voice leading and this is not a chord that has been taught to me. In fact such a bassline seems to not fit with the standard rules I have learned so far. How would a classical composer view this kind of chord progression? Would the 2nd chord be a I42? Although to be that chord wouldnt the ^7 need to resolve down to ^6? enter image description here

EDIT: Is it possible to consider this a progression in C#m aeolian or E and not in A major? Yes the cadence does seem to point back to A as the tonic but the bassline here does seems to work from a functional theory perspective if we consider that the E at the end of the progression is not a dominant but a secondary dominant.

  • Bach used your proposed second chord (but in the key of D instead of A) in the Air of the 3rd orchestral suite.
    – Peter
    Commented Sep 18, 2023 at 14:33

4 Answers 4


I would be surprised to find an example of a genuine tonic I42 in the classical repertoire, and I imagine they are not allowed by most instructions in traditional harmony, at least at first. Schonberg's Harmonielhere is one example of where it is not allowed. What is possible, is a I42 with the lowered seventh, which would de a dominant of the IV, like in the progression below:

enter image description here

Although, at least in Mozart, which is what I am more used to analyzing, it is not common at all, I would bet you could still find a few examples, and surely a lot more in Beethoven.

A textbook on (traditional) harmony will almost certainly have rules for the treatment of sevenths and for the introduction of non-scale tones (including, in this particular case, having the ^7 resolve to the ^6, like you said). The example I gave follows (I believe) the rules that Schoenberg's Harmonielehre estipulates. The dissonance is treated as a passing tone, and the non-scale tone is introduced as a direct chromaticism.

The progression you wrote, as it is, is certainly heard as being is A, but, if you are following a textbook, you should check what are the instructions given for establishing a key. Although you example is unambiguously in A, the conventional way to confirm a key would be to have the leading tone ^7 in the dominant of the final cadence.

  • Thank you. If it is in A, how can the bassline go from ^7 to ^3? That is nowhere in any of my textbooks. Yes, if you look at the minor mode but this is not the subtonic, it would be the leading tone of A going to the mediant?
    – user35708
    Commented May 3, 2022 at 11:50
  • @armani As the example stands, the leap from ^7 to ^3 will probably be considered an error, as the ^7 is a dissonance that warrants treatment. But if that ^7 was a consonance, as in the third of the V, it could leap freely, regardless of being the leading tone, although the preferred voice-leading would be for it to either go to the tonic, or stay as a common tone. Commented May 3, 2022 at 11:56
  • You are right about the cadence having the leading tone but that is precisely what someone would do if they wanted to be sneaky... have a progression that sounds like it is one key but leave out thr leading tone then introducing the leading tone of the new key just before the cadence
    – user35708
    Commented May 3, 2022 at 12:01
  • It might be an error but if we consider the passage as being C#m natural and the last chord as an applied chord to the A. Why is that not a possibility.? If you play just that bassline, it doesnt sound wrong or like an error at all. From a tonal perspective, the suggestion I made does make sense because those tones do form a bassline of an idiomatic tonal progression, just not in the same key but since the leading tone is not present then how do you know if the E7 is an applied chord or the dominant chord in A?
    – user35708
    Commented May 3, 2022 at 12:24
  • Regarding the first comment, indeed leaving out the leading tone might leave doubts about the current key, but that is not what happens with the example you provided, given no other context. If the fragment was inserted in a section that affirmed the C# minor tonality by other means then, yes, it maybe could be considered as a tonicization of the A region, not as a confirmation of it as a new tonality, depending on numerous factors.. Commented May 3, 2022 at 13:12

Don't think it can be, as there are only three notes (the triad) that make up the tonic chord. 6/4/2 is an inversion of the dominant as that dominant has 5,7,9,11 from the existing key. 6/4/2 is usually called 4/2. The 3rd inversion thereof. There isn't a 3rd inversion available for the tonic chord - unless we're talking major seventh, which is the go-to tonic for jazzers, but that's not what's asked about here.


Yes, a tonic 4/2 chord is possible. Though it would probably be part of a descending bass line.

And a G♯ bass note could be used as a dominant of C♯. But not, perhaps, with that melody.

Here's a possibility.

enter image description here

  • Thank you. Is it possible to keep the bass notes I have in my OP? that was really what I was hoping for and what my question was. How would this bassline be explained from a classical music perspective and how would the bass be harmonized. In your example the bass goes to G# but then it changes a lot.
    – user35708
    Commented May 3, 2022 at 14:19
  • As I said in my answer, I do not think a progression like this acceptable in the classical style, consequently, there is no explanation available. Commented May 3, 2022 at 15:29
  • 400 or more years of music theory and no explanation for a simple "diatonic" bassline? My word... Im sure you'll understand this when I say: How dissapointing :(
    – user35708
    Commented May 3, 2022 at 16:06
  • I never said there was no explanation for it in music theory, I said there was no justification for using it in the classical style, and I was referring mainly to the chord progression (including the bass), not just the bassline. A chromatic (not diatonic) bassline like that is pretty idiomatic in bossa-nova, for instance, you can find it in Tom Jobim's Insensatez. The harmonies involved are pretty different, however, but I would bet there are also examples of Imaj7-Imaj7/7. Commented May 3, 2022 at 17:59
  • You could also find that bassline over a different harmony in the classical repertoire, although I don't know an example by heart. Commented May 3, 2022 at 18:01


4/2 refers to a four note chord in its third inversion.

  • 1
    Yes I know but I meant a tonic chord in that inversion.. it doesnt seem to be in any of my textbooks. Only the V and ii chords seem to be in there
    – user35708
    Commented May 3, 2022 at 8:33
  • 2
    @armani If you wish to avoid answers like this, you should change the title of your question. This answers your title exactly.
    – Aaron
    Commented May 3, 2022 at 13:52
  • I dont know why an answer that correctly answers the question posed should be downvoted.
    – Neil Meyer
    Commented May 3, 2022 at 16:36
  • 1
    If the title alone is sufficient then why add a body of text? I understand your point but this answer seems to answer the title without reading the body which is supplementary... anyhow I added a bit to try and make it more specific
    – user35708
    Commented May 3, 2022 at 17:25
  • @Neil my guess is that it answers the title without reading the rest of the question
    – user35708
    Commented May 3, 2022 at 17:41

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