ascending melodic minor and false relation

Hi everyone,

I have a quick basic question that I can't really find a proper answer to. Basically, can I write the bass line in the image below? (it's not a real thing, just written to illustrate my point. I actually realize it has other problems cause I wrote it mindlessly, but I just wanna discuss the specific question below 😅)

I am in f minor, and want to make a scalar progression from D to F starting on beat 3. I  use the ascending melodic minor to avoid the augmented 2nd D-E#. But the "problem" is that I already used an unaltered D in the same measure, in both voices. It seems to me like it's akin to a false relation (even though both voices are not on D and D# at the same time). Is that a "mistake" in the classical style, or is it no problem? I also find it a bit strange to have both the D and D# in the same measure and same voice

Incidentally, it is not the focus of my question but it's also making a diminished 5th with the voice above... Is that accepted in this context? I am quite struggling with the practical details of melodic minor scales and I don't have a specific reference about it.

I don't see the problem. 

Bach did it all the time. I mean, combining different minor scales.

Invention nº2 in C minor:

Yes, I agree with Luis, there's a specific rule that says cross relationships are ok when mixing the different kinds of minor scale in the same key (one may even think that the prohibition of cross-relationships only applies 50% of the time, because there are several, very typical exceptions). Also, in your case this isn't a cross relationship even per se, because the D# and D-nat sound with several notes separating them in time.

In some extreme cases you can even find the the 2 varieties of the same note sounding literally at the same time, as in the B-natural B-sharp clashes found in the C# minor prelude of Bach's WTC-1. Another example is the "English cadence", even though this isn't common-practice harmony exactly.

thanks guys, just wanted to check that it was an alright thing to do cause I had a doubt 🙂

On 7/26/2021 at 10:27 AM, Snake_Cake said:

Yes, I agree with Luis, there's a specific rule that says cross relationships are ok when mixing the different kinds of minor scale in the same key (one may even think that the prohibition of cross-relationships only applies 50% of the time, because there are several, very typical exceptions). Also, in your case this isn't a cross relationship even per se, because the D# and D-nat sound with several notes separating them in time.

In some extreme cases you can even find the the 2 varieties of the same note sounding literally at the same time, as in the B-natural B-sharp clashes found in the C# minor prelude of Bach's WTC-1. Another example is the "English cadence", even though this isn't common-practice harmony exactly.

 

I don't see any problems with the melodic false relation(2 notes within the same measure that aren't simultaneous but are a diminished or augmented octave apart) like what @Coxi illustrates, even in major keys. And even the harmonic one can work in the right circumstances, like the dominant chord in cadences. But a harmonic one that is only justified by "I wanted some more chromaticism" and isn't from the Romantic era or beyond, that's when it becomes problematic. I say Romantic era, because you likely won't catch Beethoven, one of the transitional composers, using harmonic false relations outside where it is justified even in the Baroque(i.e. Cadences), but Chopin? Absolutely, some of the accented non-chord tones of Chopin are of the false relation type and all of the accented non-chord tones are to add expression.