WhoSampled is an iOS (and Android) app that tells you whose samples were used in the music you’re currently listening to. Just like Shazam, you hold it up to a playing tune, and WhoSampled identifies the track. But then it also gives you a breakdown of all the other songs that were sampled to make that track, and can even list cover versions.
WhoSampled is like Shazam for samples and cover versions

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