Birds sing in the morning

 to "mark their presence to others in the area".
They sing to other birds.

It's not inherited, they have to learn their song.

It's estimated that there are almost 5000 different

kinds of songbirds in the world.

I guess the learning of their song is motivated by

their instinct for survival. 

I'm worried about people who don't like singing.

They will work hard to stop others' songs, too.

With our singing we worship God.

Grateful heart sings continually.

The book of Psalms is all about singing.

"I will sing of the mercies of the Lord forever."

Psalm 89:1

I will sing, I will sing, I will sing...