Manicx: the two tunerecordings you posted is two different ones, actually Tao did three versions of that music.. one using standard YM-sounds and another using digidrums for drumsounds thats the one you recorded and calling it YM5(sid)... and a third version where he used the actual Sid-voice, thats the recording you called YM6.. it is not using sync-buzzer.
And the Sid-voice emulation is bad for the YM-format so please stop using it... YM-format is an old soundemulator format and is not very good.
files when listening on Atari ST music, they can be downloaded from Grazey's webpage, "Grazey's Zak Hacks" #21 is the first to be released in SNDH format just download every release after that to get a massive collection of Atari ST music. http://phf.atari.org
the SC68 winamp plugin can be used for playing the music (also avaible for MAC):
or Winjam: http://www.creamhq.de/