http://www.newfreeware.com/audio/
This site has a huge database on auio software, many free, many not. you wanted >4 audio tracks, but i'm confused as to what you mean so i'm on able to pinpoint exactly waht you need.
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http://www.webattack.com/
Maybe you've already looked around this site, but if not, it also has an extensive list of multimedia/audio software, downloaded freewares and sharewares.
again, if i knew waht you were talking about, i'll be of more help.