Classification (sound association): Three pairs match a source with its characteristic sound; one pair names an action rather than a characteristic sound. Identify the odd pair.

Introduction / Context:
Onomatopoeic classification uses characteristic sounds: doors bang, rain patters, drums beat. One pair breaks the pattern by naming a generic action (“play”) rather than a distinctive sound word, and thus is the outlier.

Given Data / Assumptions:

• Door → bang (sound produced on slamming).
• Rain → patter (distinctive light impact sound).
• Drum → beat (rhythmic percussive sound).
• Piano → play (an action performed on the instrument, not its characteristic sound such as “melody,” “note,” or “music”).

Concept / Approach:
Determine whether the right-hand word is a sound noun typically associated with the left-hand source. If it is an action verb/noun unrelated to onomatopoeia, it becomes the odd one out.

Step-by-Step Solution:

Verification / Alternative check:
Try paraphrasing: “The X goes Y.” The door goes bang; the rain goes patter; the drum goes beat; “the piano goes play” is ungrammatical.

Why Other Options Are Wrong:

Common Pitfalls:
Accepting musician’s action as equivalent to the instrument’s sound label. The relation specifically targets characteristic sound words.

Final Answer:
Piano : Play