Ive slightly re-arranged this song so that it may be sung as a duet. It´s Sadhbh Ni Bhruinealla I just wanted to check that it works both in context and grammatically.
The idea was to have him say to her he wants her , her to question the wisdom of going with a sea-faring man and then for them to agree to do it. Does it work in both senses?

Male/Female duet composition for Sadhbh Ni Bhruineallaigh

Male :
Ní iarrfainn de spré le Sadhbh Ní Bhruinnealla
ach Baile Inis Gé is cead éalú ar choinníní.

Chorus . Both :
Óra a Shadhbh, a Shadhbh Ní Bhruinnealla,
A chuisle is a stóirín, éalaigh is imigh liom.
(Female: a chuisle 's a stóirín ,éalóidh is imím leat )


Male:
Máistir báid mhóir mé a' gabháil ród na Gaillimhe
D'fhliuchfainn naoi bhfód is ní thóigfinn aon fharraige.


Female:
Máistir báid mhóir go deo ní ghlacfad,
Nuair a fhaigheann siad an chóir 'sé is dóichí nach bhfanann siad.

Male:
Mhionnóinn naoi n-uaire ar leabhar mór an Bhairéadaigh
Nach scarfainn go deo le Sadhbh Ní Bhruinnealla.


Female:
Fear maith i mbád thú togha fear iomraimh
Fear sluaisid' is láí ar dhá cheann an iomaire.


Male:
Nuair a thiocfas lá breá 'gus an ghaoth ón bhfarraige
Tabharfaidh mé Sadhbh liom go céibh na Gaillimhe.


end Chorus

Chorus . female only
Óra a Shadhbh, a Shadhbh Ní Bhruinnealla,
a chuisle 's a stor ,éalóidh is imím leat

Then male alone:
Óra a Shadhbh, a Shadhbh Ní Bhruinnealla,
A chuisle is a stóirín, ba rí-mhaith dhuit mise agat!

Any feedback would be great.Would love to do this song with a couple of friends but want to do it properly.

Bainigí taitneamh as!

You are probably familiar with Liam O Maonlaí's rendition in YouTube. If not, here is the link: http://www.youtube.com/watch?v=svRw6ry5x-0

Yes Im familiar with it. I think I may not have explained well what I was after. This song is usuallys sung by one person but I changed a couple of things to make it possible for it to be sung by a mixed gender couple. I was hoping someone could clarify that the changes I have made are correct and work in context of it as a duet.

For example does this work?

'a chuisle 's a stóirín ,éalóidh is imím leat ) '

its for the female part that corresponds to
''A chuisle is a stóirín, éalaigh is imigh liom''
in the mans part?

and by changing 'fear maith i mbad mé ....'

to
Fear maith i mbád thú togha fear iomraimh
Fear sluaisid' is láí ar dhá cheann an iomaire.

do the verbal tenses etc still work and make sense ?

I see that you have changed éalaigh to éalóidh, but imigh to imím.

I think you also need to change imigh to imeoidh. The future makes more sense than the habitual present - imím "I go away" sounds like she will run away every day then come back home in the evening or something. ;-).

I also think you need mé with the future tense, otherwise it is just "will elope and will go away with you".

a chuisle 's a stóirín, éalóidh mé is imeoidh mé leat

It is a mouthful, perhaps, but still singable.

You could leave out the second mé perhaps to make it a little more singable (éalóidh mé 's imeoidh leat)

The only other thing that strikes me as odd is for her to be addressing herself in the vocative:
Óra, a Shadhbh, a Shadhbh Ní Bhruinnealla...

I wonder what the name of her young man was anyway. Would make more sense for her to address him:
Óra, 'Pheadair, a Pheadair Uí Dhochartaigh... or whatever his name is.

Good point, Abigail.

Alternatively, I wonder if something like Mise Sadhbh, Sadhbh Ní Bhruinneallaigh might work, since she's making a vow, "I am Sadhbh, Sadhbh Ní Bhruinneallaigh ... and I will elope and go away with you"

éalód is imeod leat

Great input ! grma!
one little thing , I used 'imim ' as it is in the dictionary as the imperative mood for the verb , as is 'imigh' which is used in the song. Is it just a case that it sounds wierd or is this actually wrong ?