Henry Ernest Dudeney/Modern Puzzles/221 - A Musical Enigma

Modern Puzzles by Henry Ernest Dudeney: $221$

Here is an old musical enigma that has been pretty well known in Germany for some years.

1926: Henry Ernest Dudeney: Modern Puzzles ... (previous) ... (next): Unclassified Problems: $221$. -- A Musical Enigma
1968: Henry Ernest Dudeney: 536 Puzzles & Curious Problems ... (previous) ... (next): Unclassified Puzzles: $518$. A Musical Enigma