AirPlay Recorder isn't your only option for recording iTunes streams. For example, Rogue Amoeba's Audio Hijack Pro can do the job, though because it has quite a few other reasons to exist, it's not as simple or convenient as AirPlay Recorder for this purpose (and, for the same reasons, it's seen as a more legitimate app). And given the questionable nature of what it does, I suspect AirPlay Recorder's future is likely just as questionable. But while it exists, it works as advertised.
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