BUR #56704 has been approved by @nonamethanks.
mass update favgroup:53449 -> sony_mdr-series_headphones
The Sony MDR headpones should get their own tag. This is primarily the CD900ST used in The First Take and elsewhere but it looks almost identical to the 7509 except for the color of the stripe on the cup (CD900ST: post #6840489 7506: post #6154257), so I think it's worth preemptively having a tag that encompases them like the AKG headphones (forum #251256)