CoolEdit is a shareware audio editor with pretty good noise reduction capabilities...it can also boost the volume of a track without noticeable distortion which is one cool trick.

Tucows.com has it under Audio in the Win 95 (etc) section.

Now if you spend some time with this treasure trove, maybe you can transcribe some of the material for the DT -- I'm sure there'd be good variants and probably trad songs not currently in the DT.

Have fun, be good.
W-O