jade tube used as an instrument
琯 refers specifically to a jade tube used as a musical instrument, likely a type of ancient wind instrument. The meaning is narrow and concrete, centered on this ceremonial jade object.
琯 combines 王 (jade) with 官, which likely provides the sound and may relate to an official or ceremonial context. The character is rare and its exact historical development is uncertain.
The left side is 王 (jade), and the right side is 官 (official). Picture an official holding a jade tube instrument during a ceremony: 琯 is that jade instrument.
For カン, imagine a can made of jade that you blow into like a tube instrument: can -> カン, and the jade can produces a clear note.