Viccy wrote
On a side note, it's an old practice, taking a theme from music you admire and developing it. To show respect to Mozart, Chopin, Beethoven, Sor and numerous others wrote pieces based on themes from Mozart's "Magic Flute", but then they'd call it exactly that..."Variations on a Theme from the Magic Flute, by Mozart". No ambiguity.
Good point.
A lot of the undertone is not so much about the reuse itself; but about recognition & respect.
Whether by credits or royalties.