With the exception of percussion, bass trombone and some older tenor trombone music, all parts are transposing and written in the treble clef with the instrument's lowest open note (B♭ or E♭) notated as middle C. This means that for every valved instrument, from the basses to the soprano cornet, a given note on the stave corresponds to the same valve fingering, enabling players to move more easily between parts. This system is unique to UK-style brass bands, though historically the North American drum and bugle corps activity followed the brass band convention of all-treble-clef writing.