This is the 7965th most frequent Korean word.
흐르는
"Flowing" or "running."
In this sentence, '흐르는' is used as a descriptive adjective that modifies '소리가' (the sound), specifying it as the type related to flowing water.
강물이 흐르는 소리가 평화로운 느낌을 줍니다.
The sound of the river flowing gives a peaceful feeling.
Here, '흐르는' is metaphorically applied to '강물' (river) to draw a comparison with the unstoppable passage of time.
시간은 흐르는 강물처럼 멈추지 않습니다.
Time, like a flowing river, does not stop.
In this example, '흐르는' describes the motion-like presence of the music, giving it a sense of movement.