Curator of music

as someone who can't play all the instruments and isn't the greatest at actually writing out an arrangement/composition. I was hoping I could get a bunch of arrangers/composers to take modern day songs and make them even more amazing. Also taking my experience from marching band in high school our band director wrote his own compositions/arrangements of modern songs. We were a small band but tried to get lots of low brass players but that also included the saxophones. I was also thinking I'd suggest a song/songs for people to compose to and then I'd see which one I liked best from my own personal opinion. I do have a question that when I use the keyboard on the actual musescore layout if I input a note for a instrument other than a C instrument will the note automatically be transposed? or if you play C on the keyboard does it register as C or the equivalent to what C is but transposed?