to gather together, pool or collect / to happen by chance / to move close to / to exploit an opportunity
凑
=
冫
+
奏
:
The King of Chu (c) finds an abandoned popsicle (冫) in the outhouse's bathroom (ou4). He exploits this opportunity (凑) to play music (奏) by melting holes into the popsicle using a warm stream of water and thus creating a flute to play.