How do composers like Mozart and Beethoven transition keys?

[sroka]

I always wondered how they are able to do so smoothly.  And how they add accidentals that sound right in the key.  Is there a thorough explanation for this?  I feel like it's called closely related keys but I am not sure what those are and how you figure them out.

Someone enlighten me!

[49410enrique]

i believe you're thinking/asking about modulations which can be full blown changes to a new  key (closely related or distant) for a good portion of the score or as short as a few biref chords (also known as 'borrowed chords' i.e V of V, dim 7 of iv etc).

too complex and broad a topic to adequately explain here, you need a very solid understanding of fundamental music theory (including modes/modal shifts and standard harmonic progression in tradition tonal based music from the common practice periods i.e maby 1600-1890's ).

short pdf attached at least touches somewhat.

as for how the masters did it? it is a refined higher level command of the language, they are able to effortlessly move about within the confines of the compositional tradition (it is also what made what guys like Debussy did so revolutionary/counter to the norms up until that time).

pdf table contents should indicate where modulation discussion kicks in (again not comprehensive but a good short primer if you have some basics and lingo undertandig under you)

[andreslr6]

Like my music analysis teacher told us: "The difference is between just putting a faucet on a wall that 'looks nice' with no fountain, and building a whole net of pipelines behind it that connect and make the water flow". It's a nice analogy/metaphor.

[sroka]

Thank you so much for that PDF file.  This is some fantastic stuff!

[quantum]

If you want to read more on this stuff check out these books:

https://www.amazon.com/Harmony-Voice-Leading-Edward-Aldwell/dp/0495189758

https://www.amazon.com/New-Approach-Keyboard-Harmony/dp/0393950018
This books is meant to be read at the keyboard.  Playing the examples as you go along. 

I find the above two books compliment each other: the first gives a very thorough discussion on the topic, while the second gives practical instruction for executing at the keyboard. 

[andreslr6]

If you want to read more on this stuff check out these books:

https://www.amazon.com/Harmony-Voice-Leading-Edward-Aldwell/dp/0495189758

https://www.amazon.com/New-Approach-Keyboard-Harmony/dp/0393950018
This books is meant to be read at the keyboard.  Playing the examples as you go along. 

I find the above two books compliment each other: the first gives a very thorough discussion on the topic, while the second gives practical instruction for executing at the keyboard. 

Harmony and Voice Leading where the ones that my teachers kept telling us to read and from which they chose material for us to work with, (how could I forget about it?) I highly recommend it!

I didn't knew about the other one, I'll check it out too.