Peter Montgomery sent

>Bianca Among the Nightingales
>by Elizabeth Barrett Browning
The OED "jug" n3 is defined as

     An imitative representation of one of the notes of the nightingale, and
     some other birds, usually repeated as jug, jug; hence, used as a name
     for this note.

John Skelton's "To maystres Isabell Pennell" from _Garlande or Chapelet of Laurell_, (1523) is the first citation given under this use.  Skelton's combination of "jug" and "dug" combine two of the interesting words from TWL and bring up, for contemporary readers at least, another meaning of jug.  I've included the whole poem so you can enjoy the Skeltonics.  The jugs are in the final stanza.


     To maystres Isabell Pennell.

     By saynt Mary, my lady,
     Your mammy and your dady
     Brought forth a godely babi!

     My mayden Isabell,
     Reflaring rosabell,
     The flagrant camamell;

     The ruddy rosary,
     The souerayne rosemary,
     The praty strawbery;

     The columbyne, the nepte,
     The ieloffer well set,
     The propre vyolet;

     Enuwyd your colowre
     Is lyke the dasy flowre
     After the Aprill showre;

     Sterre of the morow gray,
     The blossom on the spray,
     The fresshest flowre of May;

     Maydenly demure,
     Of womanhode the lure;
     Wherfore I make you sure,

     It were an heuenly helth,
     It were an endeles welth,
     A lyfe for God hymselfe,

     To here this nightingale,
     Amonge the byrdes smale,
     Warbelynge in the vale,

     Dug, dug,
     Iug, iug,
     Good yere and good luk,
     With chuk, chuk, chuk, chuk!