Yuyake koyake (Sunrise, Sunset) is a popular children song composed by Shin Kusakawa (1893-1948) who worked as a music teacher. All over Japan, every evening at 5 p.m., this music is loudly played for 20/30 seconds and then stops. The song is used as a signal meaning that Japanese children finish school and go home.
Here is the song lyric:
夕焼け 小焼けで 日（ひ）が暮（く）れて
おててつないで みなかえろう 烏（からす）と いっしょに かえりましょう
子供（こども）が かえった あとからは
小鳥（ことり）が夢（ゆめ）を 見（み）るころは 空（そら）には きらきら 金（きん）の星（ほし）
The sunset is the end of the day,
the bell from the mountain temple rings
hand by hand let’s go back home together with the crows.
After the children are back at home
a big and round moon shines,
when the birds dream, the brightness from the stars fills the sky.
This one from Higashi Shinjuku in Tokyo.