thank you for finding these, ill fix this in svn today and you can
download the fixed tutorials from the download page
in the meantine:
define variable pi = 3.1415927, 2pi = 2 * pi
> print keynum( {{c4 e g} {d4 fs a} {e4 gs b}} )
the name is 'key':
print key( {{c4 e g} {d4 fs a} {e4 gs b}} )