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any good software to record streaming audio?

I'm guessing this is for not wholly legitimate purposes.

That said, just use a 3.5mm patch cable. One end into the headphone jack and another into the mic input of your Mac. With an audio interface, you can use a 1/4" adaptor and plug into that for better sound quality.

Then, just use something like Audacity and hit record. The default I/O configuration should be fine.
 
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