bind t to a new function #'play-this-beat, which plays the beat at point.
make //toggle play the current beat, if the music is not playing
add a variable for the root frequency.
add documentation to zmusic//current-scale
only have capital letters in hex-lookup-table, and make hex-digit-to-number upcase its argument
extract the current scale to a variable.
remove no-longer-needed comments
don't highlight the opening space of a line
move tests to a separate file.
remove testing functions
correct 'one bytes' -> 'one byte'
fix bug that plays the first beat twice when counting
make make-tone able to be big- or little-endian.
indent some code properly.
add keyword arguments so functions work either big- or little-endian.
fix missed use of //count-beat, post-rename
extract the way to combine samples into a function
use //get-beat where we can
when a new zmusic is started, don't keep the beat going