Various, Encyclopaedia Britannica, 11th Edition…
“ The mechanism and fingering are very intricate. Theoretically the whole construction of the bassoon is imperfect and arbitrary, important acoustic principles being disregarded, but these mechanical defects only enhance its value as an artistic musical instrument. The player is obliged to rely very much on his ear in order to obtain a correct intonation, and next to the strings no instrument gives greater scope to the artist.The bassoon has an eight foot tone, the compass extending from B♭ bass [1] to A♭ treble , or in modern instruments by means of additional mechanism to C or even F . ”
