mathematica moan/query

I have also discovered the mathematica sound capabilities ... and have
a problem.
Namely for certain chords - and I cannot predict which ones, but
generally more complex is worse - I get a sort of clicking or periodic
noise on top of the expected musical sound. I would guess that it is
due to some level problems, ie clipping of the waveform - but I have
no idea how to solve it. Increasing sample rate doesn't generally work.

The mathematica function 'Play' has an option to 'Automatically select
the range of function values to use for amplitudes' but it is not
clear how this could help. I have tried adjusting its values but it
only gets worse mostly...

I have noticed similar effects in synthesized sounds made by other
people occasionally, but I can't recall an example immediately.
Any ideas??
~~~T~~~