Musicians are still trained this way. The tunes in the Suzuki violin books are the ultimate covers. You can go to a beginning violin recital anywhere in the world and hear exactly the same tunes.

Musicians still use transcriptions of past recordings for their own performances.

Jazz musicians learn "standards." Even jazz improvisation, which you'd think should be 100% original, is taught using virtually the same short list of tunes, such as "Autumn Leaves."

Many musicians don't bother with original material at all, until they're absolutely sick of the standards.