Lullabies are typically sung to help babies and young children fall asleep, so the most common theme is sleep.

Nursery rhymes are simple, repetitive songs that are often used as lullabies.

Hush, Little Baby is the oldest known lullaby, dating back to the 16th century.

Rock-a-Bye Baby is often associated with the American Civil War because it was a popular lullaby among soldiers.

Twinkle, Twinkle, Little Star is often associated with the Christmas holiday because it is a popular lullaby that is often sung to children on Christmas Eve.

Twinkle, Twinkle, Little Star is the most popular lullaby in the world, and has been translated into over 100 languages.

Brahms' Lullaby is often associated with the lullaby of the Virgin Mary because it is a gentle and soothing lullaby that is often sung to babies and young children.

Hush, Little Baby is often associated with the lullaby of the Three Wise Men because it is a simple and repetitive lullaby that is often sung to babies and young children.

Rock-a-Bye Baby is often associated with the lullaby of the shepherds because it is a gentle and soothing lullaby that is often sung to babies and young children.

Twinkle, Twinkle, Little Star is often associated with the lullaby of the angels because it is a gentle and soothing lullaby that is often sung to babies and young children.

The guitar is the most common instrument used to accompany lullabies because it is a portable and versatile instrument that can be easily played by parents and caregivers.

The most common time signature used in lullabies is 4/4 because it is a simple and easy-to-follow time signature that is often used in folk songs and children's songs.

The most common key used in lullabies is C major because it is a bright and cheerful key that is often used in folk songs and children's songs.

The most common tempo used in lullabies is 60-80 bpm because it is a slow and soothing tempo that is often used in folk songs and children's songs.

The most common vocal range used in lullabies is soprano because it is a high and clear vocal range that is often used in folk songs and children's songs.