The cover formula worked

From Wikipedia:

“were a series of budget compilation cover albums of current chart hits recorded by anonymous session singers and musicians released on the Hallmark record label. They had initially reached the charts but were later disallowed due to a change in the criteria for entering the charts. These albums continued to be produced until the early 1980s, when the advent of compilation albums featuring the original versions of hits, such as the Now That’s What I Call Music series, led to a steep decline in their popularity.”

images from Jacob Whitaker