So i when to use the cello, i didn't work. then i went to use the violin also didn't work. so i tried the french horn, also didnt work.
How very descriptive...
Are you trying to put them out of their available ranges?
That's because you are blowing in the wrong end of the french horn, and the violin and cello have no strings on them
Try blowing in the other side of the french horn, and adding strings to the violin and cello