The Carpenters classic : "SING"

Sing, sing a song
Sing out loud
Sing out Strong
Sing of good things not bad
Sing of happy not sad

Sing, sing a song
Make it simple to last
Your whole life long
Don't worry that it`s not
Good enough
For everyone else to hear
Just sing, sing a song

Sing, sing a song
Let the world sing along
Sing of love there could be
Sing for you and for me

this song could be very useful in ESL classes. it`s simple and easy to memorize. I used it in my classroom to teach adjectives, it was fun!