because there are so many parts, you have to think of different structures, instruments and how they can blend together to make it sound nice. There are also other things to think about like rythms, melodies, harmonies, key changes. You can't just write random notes...it won't sound good.
He did not write the following types of concertos: viola, double bass, oboe, flute, clarinet, harp, and many more instruments. The only concertos that he has written are: Bassoon Concerto, Piano Concerto, Violin Concerto, Cello Concerto.
Tchaikovsky only wrote one violin concerto: Violin Concerto in D Major.
He only wrote one concerto, but he wrote it over 400 times.
It was something he prefered not to write for
Music
I didn't
he wrote one for violin. violin concerto in D major op. 61.
It would appear that he only wrote the one flute and harp concerto.
the cadenza in Beethoven's 3rd concerto in c minor was written out because he did not trust the piano soloists.
the Brandenburg Concerto #5
Only one concerto. K. 622.
Weber wrote two clarinet concertos, Clarinet Concerto No. 1 in F minor and Clarinet Concerto No. 2 in E-flat major.