Roll out the barrel 什么意思？？？？

这是一首歌名，可以翻译成“滚啤酒桶”

There's a garden, what a garden Only happy faces bloom there
And there's never any room there for a worry or a gloom there
Oh there's music and there's dancing
And a lot of sweet romancing
When they play the polka
They all get in the swing
Every time they hear that oom-pa-pa
Everybody feels so tra-la-la
They want to throw their cares away
They all go lah-de-ah-de-ay
Then they hear a rumble on the floor, the floor
It's the big surprise they're waiting for
And all the couples form a ring
For miles around you'll hear them sing...
Roll out the barrel, we'll have a barrel of fun
Roll out the barrel, we've got the blues on the run
Zing boom tararrel, ring out a song of good cheer
Now's the time to roll the barrel, or the gang's all here
Da-da-da-da, da-da-da-da, da-da-da-da-da-da-da-da
Then they hear a r