TY  - SER
AU  -  Gay, John, 
TI  -  The Beggar's Opera; to Which is Prefixed the Musick to Each Song 
AV  - ML 
PY  - 2008///
PB  -  Project Gutenberg, 
KW  -  Ballad operas -- Librettos
N1  -  Public domain in the USA;  Text
UR  -  http://www.gutenberg.org/ebooks/25063
ER  -