EX. 13-16B  Johannes    Martini,    J’ay    pris    amours, mm. 1–4Besides these,  there   is  a   J’ay    pris    amours  setting by  a   minor   contemporary    of  Martini and Josquin
named   Jean    Japart  in  which   the original    superius    is  actually    performed   as  the bassus, transposed  down    a
twelfth and sung    back    to  front   (the    rubric  simply  says    Vade    retro,  Sathanas:   “Get    thee    back[wards],    O
Satan”).    There   is  one by  Busnoys,    titled  J’ay    pris    amours  tout    au  rebours (“I have    taken   love    the wrong
way round”),    in  which   the original    tenor   is  inverted,   so  that    all its intervals   are turned  au  rebours.    There
is  one by  Obrecht,    clearly meant   to  be  the chanson arrangement to  end all chanson arrangements,   in  which
the superius    and tenor   are each    used    as  the cantus  firmus  twice,  migrating   systematically  throughout  a
four-part   texture.    There   is  even    an  anonymous   arrangement in  which   the treble  of  J’ay    pris    amours  is
shoehorned  into    counterpoint    with    the tenor   of  De  tous    biens   plaine.
What    was the purpose of  all this    beguiling   ingenuity?  Amusement   for the composer?   Yes,    of  course,
but not only    for the composer.   There   was an  audience    to  sustain it, a   public  audience    that    was soon    to
become, in  the classic economic    sense,  a   “market.”   The existence   of  that    audience    is  attested    by  a   new
kind    of  musical text-source called  a   partbook:   a   volume, or  rather  a   set of  volumes,    each    of  which
contains    a   single  part—superius,  tenor,  contratenor,    etc.—from   a   polyphonic  texture.    The earliest    set of
partbooks   is  the so-called   Glogauer    Liederbuch  (“Songbook  from    Glogau”),   a   set of  three   books
