"There are no filling voices anyhwere, everything is "structural".
Think about a home where the owner has filled the walls eclectic decor, just for the sake of not having a bare wall. Where the home of a designer has an overall, cohesive plan, which can even be quite minimal.
Is it like that?"
Sort of,yes. The structural miracle in Bach is ,that despite all the counterpoints ( every voice is sort of independent ) he still manages to have this amazing harmonic quality.So all the individual voices then form a harmonic progression to an organic mix that has hardly ever been matched ever since. Apart from that: his rhythmic inventiveness is also remarkable and there can be little surprise that these works still speak to us centuries after they were written,like a Shakespeare play still does.
Beethoven's beliefs are based on German idealistic philosophy ,mainly Schiller. Beethoven forces the musical material ( the notes ) into a mould , he is a welder , a blacksmith. Nothing flows natural,it is always "organized". He is awkward to play as he did not take much notice of instrumental limitations,his musical ideas supersede practicalities. His trademark is that he uses often the smallest of motif ( 5th Symphony,the famous ta-ta-ta-taaaaa ) and then creates a whole universe around it. He is not a melodic writer ,but he takes his audience and the poor performers through a journey with all ups and downs,the motifs are thrown around,distorted,magnified,amplified,repeated etc, He has essentially a positive message,the struggle ends usually well or is uplifting at least. Schiller is one of the keys to Beethoven's thinking, Friedrich Schiller - Wikipedia, the free encyclopedia
His insight into the human psyche and condition reflected in his music make him one of the greatest musical minds ever.It is a lifelong,very rewarding task to get to know and understand his music.It is not about having fun ,it's about life,and it's almost always very serious. It is very German. ( I am one of them ,so beware ! )
Key works are his 9 symphonies ( Kleiber's nr 4 and 7 a must ) , the 32 piano sonatas ( Gulda,Schnabel and Kempff to be recommended ) and the 16 string quartets ( splendid recording by the US Emerson Quartet ).
The direct line of this particular thread in classical music is : B-B-B ,Bach,Beethoven ,Brahms
( Brahms was the predominant successor of that kind of thinking in the 19th century.)
But I am a heretic. My gods are Mozart and Schubert, but that's another story.