Explain briefly some of the differences between conventional orchestras and concert or marching bands.

Don't 100% take me for this, but you could talk about how some bands, marching bands, and orchestras have different styles. Such as orchestras might play a little older music and and more conventional concert bands and or marching bands play some more recent music. Also talk about how band is an ensemble brass, woodwinds, and percussion, with instruments like baritone, french horn, trumpet, clarinet, saxophone, flute, etc. Whereas orchestras are made up more of string based instruments like violin, basses, violas, etc. Dont get me wrong though orchestras are not all string instruments but the majority are.