What Makes A Composition "coherent"?

Hi All, 

I have trouble with writing larger/longer pieces of music.

I can come up with melodies or "riffs", but I'm not sure how

to make a piece "coherent" and not simply a string of ideas,

or a "song", or ABA form.

To help me understand, I would like to start with a very simple

and short example, prelude in C by Bach, BWv924 (see attached).

Why is this piece "coherent"? What is the structure or

form of this piece?

Thanks for any help

IMSLP222728-PMLP180599-Bach_Prelude_BWV924_Cmaj.pdf

I think it is best for you learning curve to try answer your own question first.

What do you see in above example that make you think this piece is coherent?

then we can join and help you further.

I''d say that piece really is not coherent, and was likely partly written by his son. The cadenza section is rather meandering. However elements such as texture figuration, balancing 'upwards' sequences with 'downwards' sequences, etc, etc, do lend some degree of coherence to the piece.

I'd say that prelude looks like it's in binary form. What gives Bach's piece coherence is how he uses several motifs, sticks with them and develops them. Examples of this are the ascending  set of 3 sixteenths, the trilled quarter notes, and the sixteenth arpeggios. Like many of his preludes this one is based on a figuration that he develops throughout the piece.

Hi All,  

Thanks for the replies so far.

jrcramer:
I think I just assumed the piece is
coherent since it was written by Bach.
I think I can see that the piece is
divided in two sections, where the
first section has a consistant pattern
in the right hand, and where the second
section has a "somewhat" consistant
pattern also in the right hand.
I'm not sure how or why the two
sections relate to each other.

pervycreeper:
I didn't know it was partly written
by Bach's son. I guess I do see the
consistent figuration (at least in
the first half) as a kind of coherence.
I'm not sure, though, at what point
something is considered coherent or
not-coherent.

orchdork02:
If I understand correctly, the coherence
is created by the use of a particular
figuration (or group of figurations)?



I think I'm particularly confused as to
how coherence can be achieved in a
"through-composed" piece (like the Bach
piece above). In a longer piece, I
wouldn't think one can continue to use
the same figuration(s) continuously?


Thanks again for any insights
 

coherence is something you apprehend as a 'gestalt' once you get the sense that everything gels together. It is only ever possible to analyse elements that contribute to that feeling. There's nothing more to it than that

Coherence is so mainstream.

Jokz aside, I think a good way to ensure some kind of consistency is work with only a handful of small ideas. Structure, phrasing, etc should come more intuitively.

Coherence is relative. If by coherent you mean technically sound when judged against a set of rules which in some way enforces coherence these are some features that conform to the style it's written in:

Melodically, interesting mixture of easily sung leaps and steps. Favours economy over free development with the use of consistent sequences and a recurring appoggiatura motif.
Polyphonically, interesting voice leading. Lots of contrary motions between voices and implied inner voices, wedges, bariolages. Shuns bad practice like parallelism and ambiguous doubling.
Harmonically, interesting mixture of features such as clearly defined harmonic rhythms with attention paid to stresses, closely related harmonic regions and pedal point. Diatonic in the first half, slightly chromatic with g major/c minor modal mix in second.

Formally and rhythmically, nothing of note really. Arpeggios followed by cadenza in straight semiquavers. It's only written as an idiomatic keyboard writing/playing exercise. Free form but coherent nonetheless.

Hi All,  

Thanks for the additional input.

pervycreeper and Cadenza91:  
If I understand correctly, I think you're
saying that I should rely on my intuition.
I'm not sure I have much confidence in my
musical intuition at this point.

MGladman:
Thanks for the detailed analysis.
I'm taking from this that coherence
is mainly/mostly achieved in this piece
by the figuration(s) used and by the
harmonic content.
Please correct me if I'm misunderstanding.


Thanks all, I think I'm starting to get
the picture.
 

dunno m8. what do you mean by coherence? coherence is too subjective. familiar traits found in a piece of a genre we are accustomed to tend to affect our perception of its coherence. a bach piece makes as much sense as an amateur exercise full of errors to somebody who hasn't been exposed to such music. all they hear is noise. that's just my opinion. "figurations, harmonic content, etc. etc." yeah but these are but a few techniques by which coherence in the vaguest sense may be achieved, techniques that apply to some music, music that's all about motifs, melodic harmonic invention, tonality and texture, music of a particular school. there's nothing inherently coherent about textbook methods. they are broken by all great composers all the time. i'd say given enough time anything however idiosyncratic and avant garde can become coherent.
 
this topic is a bit more difficult to answer than it's meant to be. it may be more productive to ask questions that pertain to specific problems you need help with such as "how to write a classical minuet" in detail or narrow down to techniques and basics like "how to write strict counterpoint" or something.