Answer:
trumpet, cornet, Eb Bass, Eb horn, baritone, trombone, euphonium, ETC.
Actually, it depends on your definition of "brass band." There are New Orleans Brass Bands, Regimental Brass Bands, both of which encorporate woodwinds. If you're talking about the traditional British Brass Band, the standard instrumentation is:
Eb Soprano Cornet, Bb Cornet, Flugelhorn, Eb Tenor Horn, Bb Baritone, Euphonium, Tenor Trombone, Bass Trombone, Eb Bass, Bb Bass and percussion.