Nightwing

I couldn't place your tune, but there seemed to be elements of The Lincolnshire Poacher and possibly The Bonny Blue Flag.

Here's the ABc of the tune for Doodle Let Me Go given by Hugill. Note that it's modal - i.e. it's in D but all C's are natural.

As for structure, Hugill and DT give it as 4 lines - Verse, Refrain, Chorus, Refrain; Lady P gives it as 6 lines - Verse, Refrain, Verse, Refrain, Chorus, Refrain; and I've heard it as 8 lines - Verse, Refrain, Verse, Refrain, Chorus, Refrain, Chorus repeat, Refrain. As the tune is effectively two lines repeated ad lib, you can do it any way you want with the same tune.

X: 149
T:Doodle Let Me Go
M:6/8
L:1/8
S:Hugill, Shanties of the Seven Seas
K:D Mix % 1 Sharp
D|
D2E F2G|A2B c2c|B2A G2F|G3-G2B|
A3- A2F|D2F A3 |G2F E2E|D3-D3 |
D2E F2G|A2B c3 |B2A G2F|G3-G2B|
A3- A2F|D2F A3 |G2F E2E|D3-D3 ||


Wassail! V