I’m analysing Liszt’s Romance S.169 (https://musescore.com/patok/lisztromance) and I’ve noticed that the bass-line is set in different degrees of the chord it precedes. For instance, in the measures 1-5, the chord i (Em) has the tonic–E–as bass-line, but in the measure 6, the harmony changes to iiº7 and keeps the E as the bass-line, which corresponds to the minor seventh of the chord iiº. Here comes the question:
Is there any defining pattern to understand which degree of the chord must be used as the bass-line for it to sound as smooth as possible?
Let’s assume I’m writing a piece in Gm and I want to switch from i to iiº7(flat 5). I have four degrees to choose from for the bass-line: the tonic, the third, the fifth, and the seventh; which one should I choose? and on what would my choice depend?
Thanks in advance.
That is a good question. There are a few things to think about when creating your bass lines.
- You want to make sure you have a clear understanding of the current function of the chord, and the type of progression. For instance, if we are in C minor, and the chord is functioning as an opening tonic, in a tonic prolongation, your bass line is going to learn more towards a root than any other note, as your goal generally with prolongation progressions is stability. If you were to start it with a G, you would be making it less stable. That isn’t “wrong”, you just need to understand the expectation of the listener and the effect it has. In the case of a cadential 6/4 however, even though the harmony would be C-Eb-G (c minor chord) the bass would be a G, as it is really just an embellishment of the V chord.
- Beyond that, you need to think of your bass line as it’s own melody. This is the essence of good counterpoint. The place to start is with the Bach chorales. Each line in the chorale serves the harmony, but each is a melody in it’s own right. This is especially true of the soprano and the bass. Often Bach will use inversions to add interest and to smoothly connect one chord to the next.
In the case of G minor to Aø, you could do a few different things.
- Let’s say you are writing just a simple opening basic idea, and it is a tonic prolongation. You could write a progression like this: i – iiø 4/2 – V6 – i (Gm – Aø/G – D/F# – Gm). The reason it works, is because the G under the Aø leads by half-step to the F# in D.
- If you wanted to though, you could easily do the same progression in root position, and it would still sound nice.
- If however, you did not lead smoothly from the G to the F#, it wouldn’t sound very nice.
As a “tonic prolongation” idea, the first one works better to me. You can feel the tonic easier than in the second one…and you expect movement after that tonic prolongation. The second example is less “intriguing”. So maybe taking into account bass lines would be a good approach to a better tonic prolongation, is that true Jon?
Take a look at this, it helped me
In fact, even the last one works, but to my ears it’s not as smooth. It still works mostly because it is following all the other rules of harmonic syntax.