Saddest songs:-

'Na Laetha Geal M'Oige' by Enya. (I've decided on this for my funeral)
The words in Gaelic are to the effect that 'when we were young we never thought our lives would end up as they have. Now I'm old, I see that those brighter days only led to sorrow'

and

'Justju Jis Ki Thi' sung by Asha Bosle in the film Umrao Jahn.
The words (in Hindi) mean 'I never found what I was looking for, but during the search I have learned much about the world.'

Both songs mean a lot to me and bring a tear to my eye every time I hear them.