What subscription name replaced Music Key in 2015 before becoming YouTube Premium? The replacement was YouTube Red.
YouTube officially unveiled YouTube Red in October 2015 as the successor to Music Key. The change was more than a new label: YouTube broadened the subscription from a music product into a platform-wide membership. YouTube Red removed advertisements from all YouTube videos, rather than only music videos from participating labels.
The service also added background playback on mobile devices, offline viewing, and access to YouTube Originals. It was designed to compete with other paid video services while still incorporating music benefits through Google Play Music. That broader scope addressed confusion around Music Key’s definition of what counted as music content.
YouTube Red lasted until 2018, when YouTube announced a rebrand to YouTube Premium. At the same time, YouTube relaunched YouTube Music as a separate music-oriented service with its own lower-priced subscription tier. A common mix-up is treating YouTube Red and YouTube Music as identical: Red was the predecessor of the all-purpose Premium membership, while YouTube Music was the music app and service developed alongside it.