There is a traditional belief that Moses received the 10 Commandments from God on Shavuot.
Debbie Friedman wrote this song based on that tradition. Here are the lyrics:
Well there were 613 commandments that Moses handed to us.
As we stood at the foot of the mountain of Sinai
Our dear Moses started to fuss.
He threw two tablets onto the ground
And much to our surprise
The ten commandments broke into pieces
And we couldn't believe our eyes.
Because the Torah was much too long to describe to all the Jews
Our God decided to write ten commandments that said the don’t and do’s
Every commandment talked about/the way we had to live
When we work or play, cook or clean, borrow, take or give (chorus)
As we stood at the bottom of the mountain, and listened to Mosheh
He asked how many wanted the Torah, and a bunch of us said ‘Yeh’!
We thought about the way life was and the way life ought to be
Without the Torah we would have been lost, and stuck with idolatry (chor.)
So when it's time to celebrate Chag HaShavuot
We all rejoice 'cause the Torah's ours to study, teach and quote
Had we not made a promise to be chosen and to choose
Remember that there would not be a people called the Jews! (chorus)