Sadly, this is a common thing with artists with ambiguous names, and our data model only allows up to map from one Echo Nest named Artist entity to one Spotify ID.
In this case, we had mapped from that EN ID to spotify:artist:6rpTmAVssi39dK1wX5ncZT.
Looking at the Spotify data, it appears we probably should be mapping to spotify:artist:4xRYI6VqpkE3UwrDrAZL8L
We’ve updated the mapping, and it should propagate through shortly.
Please keep the error reports coming so we can make our data better.”