As a 10 year old boy in in the sanatorium in Davos, Switzerland, we sang Brahm’s lullaby (Wiegenelied) every night before the lights were turned out and we were supposed to sleep. Counting sheep is supposed to help you sleep too.

Sing along if you like.

Guten Abend, gut’ Nacht,
mit Rosen bedacht,
mit Näglein besteckt,
schlupf unter die Deck’:
Morgen früh, wenn Gott will,
wirst du wieder geweckt.

There’s even an English version, which is new to me

Lullaby and goodnight,
With roses bedight,
With lilies o’er spread
Is baby’s wee bed.
Lay thee down now and rest,
May thy slumber be blessed.

Even Bing Crosby had a go (link to Youtube)