Puzzle 17: Harmonic Families

Visual clue. Each stamp showcases a musical instrument played by blowing air through a tube, horn, or pipe.

The hook. These are traditional aerophones (wind instruments), including brass trumpets, wooden horns, and double-reed folk pipes from Europe, North Africa, and the Middle East.

Visual clue. Each stamp displays a percussion instrument designed to produce sound when struck, shaken, or beaten.

The hook. These instruments belong to the percussion family, comprising drums, frame drums, shaken tambourines, and struck bronze metallophones used in ceremonial and folk traditions.

Here's the trap we set. Players might be tempted to group stamps depicting musicians in traditional costume together rather than sorting by how the instrument itself makes sound.

Visual clue. Each stamp shows a necked string instrument with a rounded or pear-shaped soundbox, played by plucking with fingers or a plectrum.

The hook. These instruments are traditional plucked chordophones of the lute family, such as the Kazakh dombra, Moldovan cobza, Arabic oud, and Chinese ruan.

Here's the trap we set. There are eight stringed instruments in the puzzle; players who lump all string instruments together without noticing how they are played will lose a life.

Visual clue. Each stamp displays a string instrument played with a horsehair bow rather than plucked.

The hook. These are bowed chordophones, including the Indian kamaicha, Chinese erhu, Middle Eastern rebab, and Renaissance European lira da gamba.

Here's the trap we set. These four share the board with four plucked lutes. Careful observation reveals bows depicted alongside the instruments, separating bowed fiddles from plucked guitars and lutes.