Sing Old Rose
Sing Old Rose and burn the bellows. “Old Rose” was the title of a song now unknown; thus, Izaak Walton (1590-1683) says, “Let's sing Old Rose.” Burn the bellows is said to be a schoolboy's perversion of burn libellos. At breaking-up time the boys might say, “Let's sing Old Rose [a popular song], and burn our schoolbooks” (libellos). This does not accord with the words of the well-known catch, which evidently means “throw aside all implements of work.”
Now we're met like jovial fellows, Let us do as wise men tell us, Sing Old Rose and burn the bellows.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894